JP3824477B2 - Vehicle steering system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle steering apparatus in which a steering shaft coupled to a steering means such as a steered wheel is not mechanically coupled to a steering mechanism that changes the direction of a wheel.
[0002]
[Prior art]
The vehicle steering apparatus includes a link type in which a steering shaft connected to a steering means such as a steering wheel is mechanically connected to a steering mechanism, and the steering shaft is not mechanically connected to the steering mechanism. Broadly divided into linkless types.
[0003]
In the latter linkless type, for example, as described in JP-A-1-153379, the steering shaft is separated from the steering mechanism, and a steering motor as a steering actuator is provided in the middle of the steering mechanism. A steering control unit that uses a microprocessor to drive and control the steering motor according to the deviation between the actual steering angle of the steering wheel and the target steering angle. It is a configuration to adjust to.
[0004]
Further, as a linkless type, when the steering mechanism cannot be driven due to a failure of a driving means such as the steering control unit that drives the steering mechanism according to steering of the steering wheel, the steering shaft is 2. Description of the Related Art There is known a vehicle steering apparatus that includes a connecting unit that connects to the steering mechanism.
[0005]
As a connecting means for connecting the vehicle steering apparatus, an electromagnetic clutch or a friction disk disc friction clutch is used. The electromagnetic clutch is not excited when the drive means is normal, and torque transmission is interrupted. When the drive means fails, the electromagnetic clutch is energized to transmit torque from the steering shaft to the steering mechanism. It has a configuration.
[0006]
Further, the friction clutch is configured to bring the friction surface into contact with the spring force when the driving means fails, and to release the friction surface when the electromagnet is excited when the driving means is normal.
[0007]
[Problems to be solved by the invention]
However, when the steering mechanism cannot be driven due to a failure in the power supply system of the steering control unit that constitutes the driving means, steering assist by the steering motor cannot be performed, and a considerably large steering torque is applied to the steered wheels. For this reason, the electromagnetic clutch and the friction clutch require a considerably large torque transmission capacity. Therefore, there are problems that the electromagnetic clutch and the friction clutch that rotate in conjunction with the steering shaft become large, the overall size of the vehicle steering apparatus becomes large, and the steering performance of the steering means deteriorates.
[0008]
In addition, when the vehicle power supply system fails due to the explosion of the battery for starting the engine, the electromagnetic clutch does not perform the torque transmission function. Further, when the driving means is normal, the disc-shaped friction clutch needs to overcome the spring force and maintain the frictional surface separated state, and therefore a considerable current is always required.
[0009]
An object of the present invention is to provide a vehicle steering apparatus that can solve the above-described problems.
[0010]
[Means for Solving the Problems and Effects of the Invention]
  According to a first aspect of the present invention, there is provided a vehicle steering apparatus according to the steering of a steering means connected to a steering shaft supported by a stationary member without being mechanically connected to a steering mechanism that changes the direction of a wheel. In the vehicular steering apparatus provided with connection means for connecting the steering shaft to the steering mechanism when it becomes impossible to drive the steering mechanism due to a failure of the drive means for driving the steering mechanism, the connection means includes: , A locking body having a plurality of locking portions for stopping slipping, and switching to a locking position and a non-locking position for engaging with the locking portion, and when the failure occurs, the locking position And a first solenoid for switching the position of the connected body.The connecting body has an intermediate portion pivotally supported by a pivot shaft, an engaging portion capable of engaging with the locking portion at one end portion, and the other end portion coupled to a first solenoid. ingIt is characterized by that.
[0011]
  In the first aspect of the invention, when the locking mechanism is provided on one of the steering shaft and the steering mechanism and the connecting body is provided on the other, the steering mechanism cannot be driven due to a failure of the driving means. The connecting body is switched to the engaging position and engaged with the engaging portion of the engaging body, and the rotation of the steering shaft can be transmitted to the steering mechanism via the engaging body and the connecting body. When this transmission is performed, the connecting body can be locked to the locking portion of the locking body, and the rotation of the steering shaft can be transmitted without causing slipping. Compared to the above, the whole connecting means and the vehicle steering apparatus can be made compact.
  In addition, when the driving means is normal, for example, when the first solenoid is energized to switch the connecting body to the non-locking position and the steering mechanism cannot be driven due to a failure of the driving means, the first It is possible to prohibit energization of the solenoid and switch the connected body to the locking position. In this case, the first solenoid is locked to the locking portion of the locking body, and switches the position of the connecting body that transmits the rotation of the steering shaft without causing slipping. The current required by the solenoid can be reduced as compared with that using a clutch, and the entire solenoid, and thus the connecting means for connecting and the vehicle steering apparatus can be made compact. In addition, since it is possible to prohibit / energize the solenoid in conjunction with the failure of the drive means and the correction of the failure, it is possible to reliably transmit torque even when the vehicle power supply system fails. When the failure of the means is corrected, the connecting body can be automatically switched to the non-locking position by the solenoid.
[0013]
  First3The vehicle steering apparatus according to the invention is characterized by comprising prohibiting means for prohibiting energization of the first solenoid when the failure occurs.
[0014]
  This first3In the invention, when the driving means is normal, the solenoid is energized to switch the connecting body to the non-locking position, and when the steering mechanism cannot be driven due to a failure of the driving means, Energization is prohibited and the connected body can be switched to the locking position. In this case, the solenoid is locked to the locking portion of the locking body, and the position of the connecting body that transmits the rotation of the steering shaft without switching is switched, so that an electromagnetic clutch and a friction clutch are used as in the past. The current required for the solenoid can be reduced as compared with the conventional one, and the whole of the solenoid, and thus the connecting means for connection and the vehicle steering apparatus can be made compact. In addition, since the solenoid can be energized forbidden / energized in conjunction with the failure of the drive means and the correctness of the failure, torque transmission can be reliably performed even when the vehicle power supply system fails, and the failure of the drive means has been corrected. Sometimes the connected body can be automatically switched to the non-locking position by the solenoid.
[0015]
  First2The vehicle steering apparatus according to the present invention is capable of switching to a blocking position and a non-blocking position for blocking the switching of the linkage from the locking position to the non-locking position, and the linkage is moved to the locking position. A blocking body that is switched to the blocking position when switched is provided.
[0016]
  This first2In the invention, since the blocking body holds the engagement state with the locking portion of the connecting body, the switching force for the first solenoid to switch the position of the connecting body can be made relatively small, and the first solenoid As a result, the whole connecting means and the vehicle steering apparatus can be further reduced in size.
[0017]
  First4The vehicle steering apparatus according to the present invention includes a second solenoid that switches a position of the blocking body.
[0018]
  First8The vehicle steering apparatus according to the invention is characterized by comprising prohibiting means for prohibiting energization of the first and second solenoids when the failure occurs.
[0019]
  This first4Invention and No.8In the invention, the switching time of the position of the connecting body by the first solenoid is made earlier than the switching time of the position of the blocking body by the second solenoid, and the connecting body is switched to the locking position by the first solenoid. After that, since the blocking body can be switched to the blocking position by the second solenoid, even when the switching force for switching the position of the linked body by the first solenoid is relatively small, torque transmission is ensured by the linked body. It can be carried out.
[0020]
  First5The vehicle steering apparatus according to the invention includes a holding body that holds the connecting body, and the blocking body that is switched to the blocking position is sandwiched between the holding body and the connecting body.
[0021]
  This first5In the invention, when the connecting body is engaged with the locking portion, the locking body, the connecting body, the blocking body, and the holding body can be integrated, so the rigidity of the connecting body and the blocking body is relatively small. Even in this case, torque transmission can be reliably performed.
[0022]
  First6The vehicle steering apparatus according to the present invention includes a contact angle θ when the connecting body and the blocking body contact each other, an engagement reaction force N for separating the connecting body engaged with the locking portion, and the blocking body including the blocking body. When the friction coefficient μ of the contact portion in contact with the holding body is
    θ <tan^{- 1}μ
The contact angle θ is set so that
[0023]
  This first6In the invention, when the engagement reaction force N is applied to the engagement portion of the connecting body engaged with the engagement portion of the engagement body, the component force of the engagement reaction force N is obtained. A first pressing force Ncosθ for pressing the blocking body against the holding body and a second pressing force Nsinθ for pressing the blocking body to the non-blocking position are generated. In this case, it is set so that μ · N cos θ> N sin θ, in other words, tan θ <μ or θ <tan^{- 1}By setting so as to be μ, even when the load torque applied to the engaging portion is relatively high, the blocking member can be prevented from being separated by the engagement reaction force N, and the interlocking portion of the connecting body can be prevented. The engagement state can be maintained.
[0024]
  First7The vehicle steering apparatus according to the present invention includes the steering according to the steering of the steering means connected to the steering shaft supported by the stationary member without being mechanically connected to the steering mechanism that changes the direction of the wheels. In a vehicle steering apparatus comprising a connecting means for connecting the steering shaft to the steering mechanism when the steering mechanism cannot be driven due to a failure of a driving means for driving the mechanism, the connecting means includes the A gear provided on one of the steering shaft and the steering mechanism, a rocking body provided on the other and capable of switching to a locking position and a non-locking position to be engaged with the gear, and coupled to the rocking body, A first solenoid for switching the position of the oscillating body; a pin capable of switching from the locking position to the non-locking position of the oscillating body; And the rocking body is moved to the locking position. When it is replaced, characterized in that it comprises a second solenoid switching the pin to the blocking position.
[0025]
  This first7In the invention, when the driving means is normal, the first and second solenoids are energized to automatically switch the oscillator to the non-locking position and the pin to the non-blocking position, respectively. When the steering mechanism can no longer be driven due to the failure of the switch, the energization of the first and second solenoids is prohibited, and the swinging body is automatically switched to the locking position and the pin is automatically switched to the blocking position. be able to. In this case, after the first solenoid switches the rocking body that engages the gear teeth and transmits the rotation of the steering shaft without causing slippage to the locking position, the second solenoid moves the pin to the blocking position. Therefore, even when the switching force for switching the positions of the oscillating body and the pin by each solenoid is relatively small, torque transmission can be reliably performed by the oscillating body. Further, when the first and second solenoids are arranged around the gears, the holding body for holding the solenoids can be made relatively small in combination with the configuration including the swinging body. Compared with the one using a friction clutch, the whole connecting means and the vehicle steering apparatus can be made smaller.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
Embodiment 1
FIG. 1 is a schematic perspective view showing an overall configuration of a vehicle steering apparatus according to the present invention, and FIG. 2 is a partially cutaway front view showing an essential configuration of Embodiment 1 of the vehicle steering apparatus.
[0027]
This vehicle steering device includes a steering mechanism 1 for causing a pair of steering wheels A, A arranged on the left and right of a vehicle body (not shown) to perform a steering operation, and a shaft separated mechanically from the steering mechanism 1. A steering shaft 3 that is rotatably supported by a stationary member such as the housing 2, a steering wheel 4 that is connected to an upper end of the steering shaft 3 and serves as a steering means, and the steering mechanism according to the steering of the steering wheel 4 Drive means 5 for driving 1 and connection means 6 for connecting the lower end of the steering shaft 3 to the steering mechanism 1 when the steering mechanism 1 cannot be driven due to a failure of the drive means 5. It becomes the composition.
[0028]
The shaft housing 2 that supports the steering shaft 3 is provided with a reaction force actuator 7 that applies a reaction force opposite to the steering direction to the steered wheels 4. The reaction force actuator 7 is driven in both forward and reverse directions by energization from a drive circuit 70 in accordance with an operation command signal provided from a steering control unit 52 provided later in the drive means 5, and the steering direction of the steered wheels 4 is determined. An operation to apply a reverse force (reaction force) is performed.
[0029]
Therefore, it is necessary to apply a steering torque against the reaction force generated by the reaction force actuator 7 to steer the steered wheels 4. The torque sensor 8 for detecting the steering torque, the steering amount and the steering direction of the steered wheels 4 are determined. For example, a rotary encoder 9 to be detected is attached to the shaft housing 2, and the results detected by the torque sensor 8 and the rotary encoder 9 are given to the steering control unit 52 via the interface circuit 10. Note that a potentiometer or a resolver may be used instead of the rotary encoder 9.
[0030]
As is well known, the steering mechanism 1 connects both ends of a steering shaft 11 that extends in the left-right direction of the vehicle body and moves in the axial length direction, and knuckle arms 12 and 12 that support the wheels A and A. Then, the knuckle arms 12 and 12 are pushed and pulled by the movement of the steering shaft 11 in both directions, and the wheels A and A are steered left and right. This steering is coaxial with the middle portion of the steering shaft 11. The rotation of the brushless type steering motor 51 configured as described above is converted into the movement of the steering shaft 11 by an appropriate motion conversion mechanism.
[0031]
The steering shaft 11 is provided with a spiral groove on one end side in the axial direction and a rack tooth on the other end side. The steering shaft 11 is not rotatable in the shaft housing 13 and is supported so as to be movable in the axial direction. ing. A pinion shaft 16 having a pinion meshing with the rack teeth at the lower end and a transmission shaft 15 connected to the upper end via a joint 14 is rotatably supported in the shaft housing 13, and the drive means 5 fails. In this case, the steering shaft 11 is moved by rotating the pinion shaft 16. The shaft housing 13 is provided with a rotary encoder 20 that detects the amount and direction of rotation of the pinion shaft 16, and the result detected by the rotary encoder 20 is given to the steering control unit 52 via the interface circuit 10. Yes.
[0032]
The steering motor 51 is supported so as to be rotatable between a cylindrical stator fixed in the shaft housing 13 that supports the steering shaft 11, and an inner peripheral surface of the stator and an outer peripheral surface of the steering shaft 11. And a cylindrical rotor having a plurality of permanent magnets spaced apart in the circumferential direction. A transmission ring that engages with a spiral groove provided in the steering shaft 11 is connected to the rotor, and the rotation of the steering motor 51 is transmitted to the steering shaft 11 through the transmission ring, and the steering The shaft 11 is configured to move in the axial direction.
[0033]
The driving means 5 includes the steering motor 51 and a steering control unit 52 using a microprocessor. The steering motor 51 is rotated by energization from the drive circuit 50 given from the steering control unit 52, and the rotation of the steering motor 51 is converted into sliding in the axial direction of the steering shaft 11. Steering (steering wheels A and A for steering) is performed according to the rotation of the motor 51. The steering control unit 52 starts an operation in response to an on operation of a key switch for starting the engine.
[0034]
3 is an enlarged cross-sectional view taken along line III-III in FIG. 2, and FIG. 4 is an enlarged cross-sectional view in a state where the connecting body and the blocking body are switched.
The coupling means 6 has a plurality of locking portions 61a that stop slipping in the rotation direction on the peripheral surface, and engages with the locking body 61 that is a gear and the locking portion 61a that is a tooth. 3 and a connecting body 62 that is a swinging body that can be switched to the locking position when a failure of the steering control unit 52 occurs. A body 62 is connected to the pinion shaft 16 via a cylindrical holding body 63, and the locking body 61 is connected to the steering shaft 3 via a cylindrical rotating body 64.
[0035]
One end of the rotating body 64 is fitted and fixed to the lower end of the steering shaft 3, the annular locking body 61 is fitted and fixed to the outer periphery of the other end, and bearings 65 are provided on both sides of the locking body 61. , 65 are provided, and the rotating body 64 and the holding body 63 can be rotated relative to each other via the bearings 65, 65.
[0036]
The locking body 61 is made of a gear provided with a plurality of locking portions 61a that are teeth on the outer periphery of an annular portion 61b having a fitting hole that is fitted to the outer periphery of the rotating body 64. The engaging portion 61a has a sawtooth-like or spline-like continuous tooth shape, and its shape is not particularly limited.
[0037]
The other end of the holding body 63 is fitted and fixed to the transmission shaft 15, and is connected to the connecting body 62 and the connecting body 62 at an intermediate portion, and the connecting body 62 is moved to the locking position and the non-locking position. Using the first solenoid 66 to be switched, and a pin that can be switched to the blocking position of FIG. 4 and the non-blocking position of FIG. 3 to prevent the connecting body 62 from switching from the locking position to the non-locking position. When the connecting body 62 is switched to the locking position, a blocking body 67 that is switched to the blocking position, and a second block that is connected to the blocking body 67 and switches the blocking body 67 to the blocking position and the non-blocking position. A solenoid 68 is provided.
[0038]
Further, in the intermediate portion of the holding body 63, a notch hole 63a facing the outer peripheral side of the locking body 61 and a seat that is arranged in the notch hole 63a and abuts when the blocking body 67 is cut to the blocking position. 63b and a pair of recesses 63c and 63d communicating with the notch hole 63a are provided. The connecting body 62 is pivotally supported in the cutout hole 63a via a pivot shaft 69 parallel to the axis of the steering shaft 3, and the first and second solenoids 66 are disposed in a pair of recesses 63c and 63d. 68 are accommodated.
[0039]
These first and second solenoids 66 and 68 are attracted and moved backward by energizing the electromagnetic coil from the power source via a relay (not shown) in response to an operation command signal from the steering control unit 52. Movable iron cores 66a and 68a, and spring bodies 66b and 68b for moving the movable iron cores 66a and 68a forward when energization of the electromagnetic coil is prohibited due to a failure of a vehicle power supply system or an operation of turning off a key switch, etc. The connecting body 62 is connected to the movable iron core 66 a of the first solenoid 66, and the blocking body 67 is connected to the movable iron core 68 a of the second solenoid 68.
[0040]
Further, the first and second solenoids 66 and 68 require a current necessary for advancing the movable iron cores 66a and 68a by a current necessary for attracting and holding the movable iron cores 66a and 68a by energizing the electromagnetic coils. Since it can be reduced to about 1/5 compared to the current, and the suction state of the movable iron cores 66a and 68a can be maintained by this low current, the connecting body 62 is brought into the unlocked position by the suction of the movable iron cores 66a and 68a. Further, when the blocking body 67 is switched to the non-blocking position, the current supplied to the electromagnetic coil by the steering control unit 52 is lowered.
[0041]
The connecting body 62 uses an arm-like rocking body. One end of the connecting body 62 is provided with an engaging portion 62a (protrusion) that engages with the locking portion 61a, and the other end is provided with a long hole 62b. It is connected to the movable iron core 66a of the first solenoid 66 through a pin 70 inserted into 62b.
[0042]
The blocking body 67 uses a pin integrally connected to the movable iron core 68a of the second solenoid 68, and an inclined guide surface 67a is provided at the end edge thereof.
[0043]
In the vehicle steering apparatus configured as described above, when the driving means 5 such as the steering control unit 52 and the steering motor 51 are normal, the steering control unit 52 responds to the steering of the steering wheel 4. 51 is driven and controlled, and the steering motor 51 drives the steering mechanism 1 to cause the steering wheels A and A to perform a steering operation.
[0044]
At this time, a steering torque against the reaction force generated by the reaction force actuator 7 is applied to the steering wheel 4. This steering torque is detected by the torque sensor 8, and the steering amount of the steered wheels 4 is detected by the rotary encoder 9 including the steering direction, and these detection results are given to the steering control unit 52.
[0045]
Further, the first and second solenoids 66 and 68 of the connecting means 6 are energized to the electromagnetic coil via the relay by the steering control unit 52, and the connecting body 62 stops at the non-locking position, and the blocking body. 67 is stopped at the non-blocking position, but the first solenoid 66 may be provided with a spring body 66b having a small spring force enough to switch the connecting body 62, and the second solenoid 68 may be a blocking body. Since the spring body 68b having a spring force small enough to switch 67 may be provided, a low current solenoid can be used for both. Therefore, the size can be reduced as compared with the conventional case of using an electromagnetic clutch and a disk-type friction clutch.
[0046]
Further, when, for example, the steering control unit 52 of the driving means 5 breaks down and the steering mechanism 1 cannot be driven, a control unit (not shown) different from the steering control unit 52, in other words, For example, the relay is cut off by a prohibiting means for prohibiting energization, and energization of the electromagnetic coils of the first and second solenoids 66 and 68 is prohibited.
[0047]
Along with this, the movable iron core 66a of the first solenoid 66 moves forward by the force of the spring body 66b, the connecting body 62 is switched to the locking position, and the engaging portion 62a of the connecting body 62 locks the locking body 61. Engage with the part 61a. After the connecting body 62 is switched to the locking position, the movable iron core 68a of the second solenoid 68 is moved forward by the force of the spring body 68b, the blocking body 67 is switched to the blocking position, and the blocking body 67 is guided. The surface 67a is sandwiched between the receiving seat 63b and the connecting body 62 while abutting against the edge of the connecting body 62, and the switching of the connecting body 62 to the non-locking position can be reliably prevented. The mechanism 1 can be mechanically connected via the rotating body 64, the locking body 61, the connecting body 62, and the holding body 63.
[0048]
A considerably large steering torque applied to the steering wheel 4 can be reliably transmitted to the steering mechanism 1 via the steering shaft 3, the locking body 61, the connecting body 62, the blocking body 67, the receiving seat 63 b, and the holding body 63. The steering mechanism 1 can be driven reliably.
[0049]
When the failure of the steering control unit 52 is corrected by the repair and the steering mechanism 1 can be driven by the driving means 5, the electromagnetic coils of the first and second solenoids 66 and 68 are energized. .
[0050]
As a result, the movable iron core 68a of the second solenoid 68 moves backward, and the blocking body 67 is switched to the non-blocking position. After the blocking body 67 is switched to the non-blocking position, the movable iron core 66a of the first solenoid 66 moves backward, the connecting body 62 is switched to the non-locking position, and the engaging portion 62a of the connecting body 62 is engaged. Detach from the stop 61a. Accordingly, transmission of steering torque from the locking body 61 to the connecting body 62 is blocked.
[0051]
In the above-described embodiment, when the steering mechanism 1 cannot be driven due to a failure of the steering control unit 52, the steering motor 51 cannot perform steering assistance, and the steering wheel 4 is considerably steered. In order to apply torque, when the steering control unit 52 breaks down, the torque sensor 8 provided in the shaft housing 2 that supports the steering shaft 3 is used, and the detection result detected by the torque sensor 8 is used. The steering control unit 52 is provided separately from the steering control unit 52, and an operation command signal is given to the driving circuit 50 of the steering motor 51 from the separate steering control unit to drive the steering motor 51. Then, the steering operation may be performed with the same feeling as that of a steering apparatus capable of performing general steering assistance in which the steering wheel 4 and the steering mechanism 1 are mechanically coupled.
[0052]
Further, in the embodiment described above, instead of providing the locking body 61 on the steering shaft 3 side and providing the connecting body 62 and the blocking body 67 on the steering mechanism 1 side, the connecting body 62 and the steering body 3 on the steering shaft 3 side are provided. It is good also as a structure which provided the blocking body 67 and provided the said locking body 61 in the steering mechanism 1 side.
[0053]
In addition, the connecting body 62 and the blocking body 67 are each one, or a plurality of connecting bodies 62 and a blocking body 67 may be provided, and the connecting body 62 and the blocking body 67 may be equally arranged at the circumferential position of the locking body 61.
[0054]
Further, in addition to the connection body 62 and the blocking body 67, the blocking body 67 may be omitted, and the steering torque may be transmitted via the locking body 61 and the connection body 62.
[0055]
The connecting body 62 may be configured to be able to swing in the radial direction of the locking body 61, or may be configured to be movable in the radial direction of the locking body 61. It is good also as a structure which can move to an axial length direction. When the connecting body 62 is configured to be movable in the radial direction of the locking body 61, for example, a connecting body using a pin or a ball that can move along the guide hole is used, and the connecting body is moved to the locking position. It is set as the structure provided with the solenoid which switches the spring body and the connection body which urge | bias to a non-locking position. Further, when the connecting body 62 is configured to be movable in the axial length direction of the locking body 61, for example, the connecting body 62 using a pin that can be moved along the guide hole is used. The solenoid is switched.
[0056]
Embodiment 2
FIG. 5 is an enlarged view showing a main configuration of the second embodiment.
The vehicle steering apparatus according to the second embodiment relates to the contact angle θ when the connecting body 62 switched to the locking position and the blocking body 67 switched to the blocking position are in contact with the locking portion 61a. When the engagement reaction force N that separates the combined connecting body 62 and the friction coefficient μ of the contact portion where the blocking body 67 contacts the seat 63b,
θ <tan^-1μ
The contact angle θ is set so that
[0057]
In the second embodiment, the blocking body 67 switched to the blocking position is such that the corner portion 67c formed by one side surface 67b of the guide surface 67a is in contact with the surface 62c opposite to the engaging portion 62a of the connecting body 62. Contact with θ. When the steering torque applied to the steering wheel 4 is transmitted from the steering shaft 3, the locking body 61, the connecting body 62, the blocking body 67 and the receiving seat 63 b to the holding body 63, the engagement reaction that separates the connecting body 62 is performed. A force N is generated, and two component forces of the engagement reaction force N are applied to the blocking body 67. One component force is a first pressing force Ncosθ that presses the blocking body 67 against the receiving seat 63b, and the other one component force is a second pressing force Nsinθ that presses the blocking body 67 to the non-blocking position. The first pressing force Ncosθ and the second pressing force Nsinθ are set such that μ · Ncosθ> Nsinθ, thereby preventing the blocking body 67 from moving away from the connecting body 62 due to the reaction force of engagement. it can. Since the relationship between N cos θ and N sin θ is N sin θ / N cos θ = tan θ, the contact angle θ is θ <tan^-1It can be set by μ. Further, when the friction coefficient μ is increased, there is a concern that the movement of the blocking body 67 from the non-blocking position to the blocking position and the movement from the blocking position to the non-blocking position may be deteriorated. The friction coefficient is set in advance.
[0058]
Since other configurations and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals, and detailed descriptions and descriptions of the operations are omitted.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an overall configuration of a vehicle steering apparatus according to the present invention.
FIG. 2 is a partially cutaway front view showing the main configuration of the first embodiment of the vehicle steering apparatus according to the present invention.
FIG. 3 is an enlarged cross-sectional view taken along line III-III in FIG.
FIG. 4 is an enlarged cross-sectional view of the vehicle steering apparatus according to the present invention in a state where the positions of the connecting body and the blocking body are switched.
FIG. 5 is an enlarged view showing the main configuration of a second embodiment of the vehicle steering apparatus according to the present invention.
[Explanation of symbols]
1 Steering mechanism
2 Static side member (shaft housing)
3 Steering shaft
4 Steering means (steering wheels)
5 Drive means
6 connection means
61 Locking body (gear)
61a Locking part (tooth)
62 Linking body (rocking body)
63 Holder
64 Rotating body
66, 68 solenoid
67 Blocker (pin)

Claims (8)

Due to the failure of the drive means that drives the steering mechanism in response to the steering of the steering means connected to the steering shaft supported by the stationary member without being mechanically connected to the steering mechanism that changes the direction of the wheel In the vehicle steering apparatus including a connecting unit that connects the steering shaft to the steering mechanism when the steering mechanism can no longer be driven, the connecting unit has a plurality of locking portions that stop slipping. A locking body, a switching body that can be switched to a locking position and a non-locking position that engage with the locking portion, and a switch that is switched to the locking position when the failure occurs, A first solenoid for switching a position, and the connecting body has an engaging portion that is pivotally supported by a pivot shaft at an intermediate portion and can be engaged with the locking portion at one end. car, characterized in that the end portion is connected to the first solenoid Use steering system. It is possible to switch to a blocking position and a non-blocking position that prevent the connecting body from being switched from the locking position to the non-locking position. When the connecting body is switched to the locking position, to the blocking position. vehicle of which claim 1 Symbol mounting comprises a switching is obstructing body steering system. The vehicle steering system according to claim 1 or claim 2 and a prohibiting means for prohibiting the energization of the first solenoid when the fault occurs. The vehicle steering apparatus according to claim 2, characterized in that a second solenoid for switching the position of the blocking member. Wherein a holding member for holding the joint body, the blocking said holding body switched obstructing body to position and joint body vehicle steering system according to claim 2 or claim 4 wherein are to sandwich between. Contact angle θ when the connecting body contacts the blocking body, engagement reaction force N for separating the connecting body engaged with the locking portion, friction of the contact portion where the blocking body contacts the holding body When the coefficient μ is
θ <tan ^{- 1} μ
The vehicle steering apparatus according to claim 5, wherein the contact angle θ is set so that   Due to the failure of the drive means that drives the steering mechanism in response to the steering of the steering means connected to the steering shaft supported by the stationary member without being mechanically connected to the steering mechanism that changes the direction of the wheel In the vehicle steering apparatus provided with connection means for connecting the steering shaft to the steering mechanism when the steering mechanism can no longer be driven, the connection means is connected to one of the steering shaft and the steering mechanism. A gear provided on the other side, an oscillating body provided on the other side and capable of switching to a locking position and an unlocking position engaging with the gear; And a pin that can be switched to a blocking position and a non-blocking position that prevent the switching of the rocking body from the locking position to the non-locking position, and the rocking body is connected to the pin. When switched to Vehicle steering apparatus, comprising a second solenoid switching the stop position. The vehicle steering apparatus according to any one of claims 4 to 7 , further comprising prohibiting means for prohibiting energization of the first and second solenoids when the failure occurs.

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