JP4211770B2 - Vehicle steering system - Google Patents

Description

  The present invention relates to a vehicle steering apparatus.

  A power steering device that assists a driver's steering operation force is known (see, for example, Patent Document 1). In this type of device, a hydraulic or electric actuator is connected to a steering shaft that is mechanically connected to a steering mechanism, and the driver's steering operation force is assisted by the actuator when the steering operation requires a particularly large steering force. .

  In addition, a vehicle steering apparatus that performs steering by an actuator according to a driver's steering operation is known (see, for example, Patent Document 2). In this type of device, the steering shaft and the steering mechanism are not mechanically connected, and the steering actuator is controlled according to the steering operation angle, and the steering mechanism is driven by the steering actuator to perform the steering. Is going. The operation reaction force is generated by a reaction force generating actuator connected to the steering shaft.

Prior art documents related to the invention of this application include the following.
JP 09-277948 A JP-A-10-226352

  In the latter vehicle steering device described above, the relationship between the steering operation angle and the actual steering angle (hereinafter referred to as the steering gain) can be finely controlled in accordance with the vehicle speed or the like, so the steering gain can be adjusted according to the vehicle speed. It is possible to realize vehicle control such as continuously changing and making the yaw rate at the time of steering constant.

  However, in a general steering mechanism, the required steering torque increases as the rudder angle increases.Therefore, if the latter steering system is used, a steering actuator having a large capacity must be installed. There is a problem that the energy consumption increases and the vehicle weight and installation space increase.

  Further, in the latter vehicle steering device, the operation must be stopped when a failure occurs in the steering actuator and its driving device.

The deformable wire means connected to the steering mechanism and the input side are connected to the operating means, and the output side is connected to the deformable wire means, and the operation means and the steering mechanism are connected and disconnected via the wire means ( After the shaft is connected, the steering drive means is controlled so that the steering angle detection value becomes the target steering angle corresponding to the operation angle detection value when the shaft is disconnected. The steering mechanism is driven by using the operating force of the driver by the operating means as the driving force for driving the steering mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, emergency steering at the time of an apparatus failure is attained, aiming at the capacity reduction of a steering actuator, and the freedom degree of the layout of a vehicle interior and the shock absorption power of a steering apparatus can be increased.

FIG. 1 shows the configuration of an embodiment.
In this embodiment, the example which steers the wheel 2 by the steering mechanism 1 of a rack and pinion type is shown. An electromagnetic clutch 7 is provided between the steered shaft 4 to which the pinion 3 of the steering mechanism 1 is coupled and the steering shaft 6 to which the steering wheel 5 is coupled, and the electromagnetic clutch 7 allows the steering shaft 4 and the steering shaft 6 to be connected. Connection and disconnection (hereinafter simply referred to as shaft connection and shaft disconnection) are performed. A steered motor 9 is connected to the steered shaft 4 via a worm gear 8, and the steering mechanism 1 is driven by the steered motor 9 to steer. A steering angle detection sensor 10 is directly connected to the steering motor 9 to detect the steering angle of the wheels 2 and the rack stroke of the steering mechanism 1.

  A reaction force generation motor 12 is connected to the steering shaft 6 via a worm gear 11, and the reaction force generation motor 12 generates a reaction force against the steering operation. The steering shaft 6 is also provided with an operation resistance generator 13 composed of a spring and a damper, and mechanically generates a resistance force to the steering operation. An operating angle detection sensor 14 is directly connected to the reaction force generating motor 12 to detect the operating angle of the steering wheel 5.

  In this embodiment, a steering wheel 5 side device from the steering motor 9 and the steering angle detection sensor 10, that is, the steering motor 9, the steering angle detection sensor 10, the electromagnetic clutch 7, the reaction force generation motor 12, and An operating angle detection sensor 14 is installed in the vehicle interior. Thereby, compared with the case where these apparatuses are arrange | positioned in an engine room, it is not received to the influence of the heat which an engine emits, and can improve the reliability of a steering apparatus.

  In this embodiment, although an example in which an electric motor is used for the steering actuator and the reaction force generating actuator is shown, a hydraulic motor can also be used. The types of the steering motor and the reaction force generating motor are not particularly limited, and a DC motor or an AC motor can be used.

  The controller 15 includes a microcomputer (not shown) and a motor drive circuit. The controller 15 executes a steering control program, which will be described later, to control the electromagnetic clutch 7, the steering motor 9, and the reaction force generation motor 12. Rudder. A vehicle speed detection sensor 16 is connected to the controller 15. The vehicle speed detection sensor 16 is provided, for example, on the output shaft of the transmission, and generates a vehicle speed pulse signal for each predetermined travel distance. The controller 15 counts the vehicle speed pulse signal from the vehicle speed detection sensor 16 to detect the travel distance, and detects the vehicle speed based on the pulse time interval of the vehicle speed pulse signal and the number of pulses per predetermined time.

  In the configuration of the above embodiment, the steering wheel 5 is the operation means, the operation angle detection sensor 14 is the operation angle detection means, the steering motor 9 is the steering drive means, and the steering angle detection sensor 10 is the steering. The angle detection means, the reaction force generation motor 12 as the reaction force generation means, the electromagnetic clutch 7 as the shaft connection / disconnection means, the controller 15 as the control means and the vehicle state determination means, and the vehicle speed detection sensor 16 as the vehicle speed detection means and the traveling Each of the distance detection means is configured.

  In this embodiment, during normal traveling, the electromagnetic clutch 7 is released to separate the steering shaft 6 and the steered shaft 4, and the steering mechanism 1 is driven by the steering motor 9 to steer the wheels 2. On the other hand, at the time of stationary, the electromagnetic clutch 7 is connected to directly connect the steering shaft 6 and the steered shaft 4, and the driving force of the steering motor 9 and the reaction force generating motor 12 and the operation of the steering wheel 5 by the driver. The steering mechanism 1 is driven by the force, and the wheels 2 are steered.

  In the above-described conventional power steering device, the driver's steering operation is assisted by the driving force of the actuator at the time of a stationary operation that requires a large steering force. On the other hand, in this embodiment, the maximum output of the steering motor 9 is set to a value smaller than the maximum steering force required to perform the stationary operation up to the maximum steering angle, and at the stationary operation where a large steering force is required. Assisting the shortage of the output of the steering motor 9 by the driver's steering operation.

  By reducing the maximum output of the steering motor 9, energy consumption during stationary steering of the steering motor 9 can be reduced, and the motor itself becomes smaller and lighter, which reduces installation space and vehicle weight. You can plan.

  In this embodiment, if the actual rudder angle deviates significantly from the target rudder angle during normal traveling, it is determined that the steering device including the steering motor 9 and the controller 15 is broken, and the electromagnetic clutch 7 is connected. The steering shaft 6 and the steered shaft 4 are directly connected. As a result, emergency steering becomes possible, and the operation can be continued for the time being.

  FIG. 2 shows the characteristic of the steering gain G with respect to the vehicle speed V [km / h] of the steering device of this embodiment. When the vehicle speed V is less than or equal to the predetermined value V1, the steering gain G is kept constant at the predetermined value G1. When the vehicle speed V exceeds the predetermined value V1, the steering gain G is gradually reduced as the vehicle speed V increases, and when the vehicle speed V increases, the steering gain G is made constant. The reduction rate of the steering gain G in the range where the vehicle speed V is greater than the predetermined value V1 is along a curve that makes the yaw rate at the time of turning almost constant.

  At a low vehicle speed where the vehicle speed V is equal to or lower than the predetermined value V1, a value larger than the steering gain of a conventional general vehicle is set as the steering gain G. For example, the entire operation range of the steering wheel 5 is set to be within one rotation, and the steering gain is set such that the steering angle of the wheel 2 is maximized on the left and right within each half turn from the steering neutral position of the steering wheel 5 to the left and right. As a result, the steering angle changes greatly with a slight steering operation angle when the vehicle is stationary, and the maximum steering angle can be operated without changing the steering wheel 5 when the vehicle is stationary, thereby improving operability.

  During normal travel, the electromagnetic clutch 7 is released to separate the steering shaft 6 and the steered shaft 4, and the steering motor 9 is set so that the rudder angle of the wheel 2 becomes a target rudder angle obtained by multiplying the steering operation angle by the steering gain G. The steering mechanism 1 is driven by the steering motor 9 to steer the wheels 2. As shown in FIG. 2, the steering gain decreases as the vehicle speed V increases during normal traveling. Therefore, the steering angle changes slightly even when the steering is greatly operated during high-speed traveling, and the safety can be improved.

  At the time of stationary, the electromagnetic clutch 7 is turned on to connect the steering shaft 6 and the steered shaft 4, and the steering gain G at this time is constant G2 shown in FIG. The steering gain G2 at the time of the shaft connection is set to be about the same as that of a conventional general vehicle.

  FIG. 3 shows the torque required when the steering mechanism 1 is stationary with respect to the rack stroke. Although FIG. 3 shows a positive required torque for a positive rack stroke, the required torque for a negative rack stroke is the same except that the polarity is negative, and the illustration is omitted.

  Because of the link efficiency between the tie rod of the steering mechanism 1 and the knuckle arm (not shown), the required torque for a steep increase increases when the rack stroke exceeds a predetermined value R1, and the maximum required torque for a maximum rack stroke is reached at the maximum rack stroke. There is. In this embodiment, as shown in FIG. 3, the maximum torque of the steering motor 9 is set to T1, which is about half of the maximum stationary torque, and the maximum rack stroke that can be driven with the maximum torque T1 is set to R1.

  Here, since the maximum output of the steering motor 9 is obtained by multiplying the maximum torque T1 of the steering motor 9 by the motor rotational speed determined by the reduction ratio of the worm gear 8, when converted into the output, the steering motor The maximum output of 9 is approximately half of the maximum steering force required to perform the stationary up to the maximum steering angle. The maximum output of the steering motor 9 does not necessarily have to be half of the required maximum turning force, and may be a value that is at least smaller than the required maximum turning force.

  Since the maximum output of the steering motor 9 is almost half of the required maximum steering force, naturally, the steering mechanism 1 cannot be driven more than the rack stroke R1 by the steering motor 9 when it is stationary. Therefore, in this embodiment, the electromagnetic clutch 7 is connected at the time of stationary and the steering shaft 6 and the steered shaft 4 are coupled, so that the output shortage of the steered motor 9 is compensated by the steering operation force of the driver. .

  FIG. 4 shows a rack stroke with respect to a steering operation angle according to an embodiment. 4 shows a positive rack stroke with respect to a positive operation angle, the rack stroke with respect to a negative operation angle is the same except that the polarity is negative, and the illustration is omitted.

  Since the steering gain when the steering shaft 6 and the steered shaft 4 are connected by connecting the clutch 7 is smaller than the steering gain when the steering shaft 6 and the steered shaft 4 are disconnected by releasing the clutch 7, The rack stroke with respect to the steering operation angle differs when the shaft is separated, and the maximum steering operation angle that achieves the maximum rack stroke also differs.

  Steering operation is frequently performed when entering a garage or parking, and is often operated up to the maximum steering operation angle. In such a case, if the maximum rack stroke with respect to the maximum steering operation angle, that is, the maximum steering angle changes, the driver feels uncomfortable. Therefore, in this embodiment, the maximum rack stroke with respect to the maximum steering operation angle, that is, the maximum steering angle is set to be the same when the shaft is connected and when the shaft is disconnected.

  Specifically, as shown in FIG. 4, a straight line having an inclination determined by a steering gain G2 (see FIG. 2) when the steering shaft 6 and the steered shaft 4 are connected from the point P1 of the maximum rack stroke at the maximum steering operation angle. (Characteristic 2 in the figure) is drawn, and the intersection point with the rack stroke R1 that can be driven by the steering motor 9 is P2, and the steering operation angle at the intersection point P2 is S1. The intersection P2 is used as an open / close switching point of the electromagnetic clutch 7, and when it is stationary, the electromagnetic clutch 7 is released to the steering operation angle S1, and the electromagnetic clutch 7 is connected at the steering operation angle S1 or more.

  When the shaft is separated, turning is performed by the steering motor 9, and the rack stroke with respect to the steering operation angle at that time is changed along the curve of the characteristic 1 shown in FIG. The curve of characteristic 1 is a curve in which the rack stroke increases in proportion to the operation angle in a range where the steering operation angle is small, but the rack stroke increases abruptly as the operation angle approaches S1.

  Therefore, when the steering wheel 5 is operated to the maximum operating angle during the stationary operation, the rack stroke suddenly increases in the vicinity of the operating angle S1, and when the operating angle S1 is exceeded, the rack stroke gradually increases. In other words, according to this embodiment, the steering gain changes abruptly near the operation angle S1, but stationary steering is performed at the time of stopping such as when entering a garage or parking or at an extremely low speed. Even if it changes, it is thought that it does not give the driver a great sense of incongruity. Rather, by changing the steering gain in the middle, the steering angle can be adjusted to the maximum rudder angle when the vehicle is stationary in the stationary state, and the steering angle can be steered to the maximum rudder angle while the shaft is disconnected at low speeds. The operating angle when operated can be made the same, and in any case, if the steering wheel 5 is rotated about ½ from side to side from the steering neutral position, the left and right maximum steering angle can be obtained. Steering operability is improved.

  FIG. 5 shows the torque required for turning when starting from a state where the vehicle is stopped while turning. In addition, in FIG. 5, although the characteristic with respect to a positive required steering torque is shown, the characteristic with respect to a negative required steering torque is also the same, and illustration is abbreviate | omitted.

  The required turning torque when starting from a state where the vehicle is stopped while being steered is the sum of the torque resulting from deformation of the tire due to stationary and the self-aligning torque during traveling, and the travel distance from the stationary state Strictly speaking, generally, there is a tendency shown in FIG. 5 according to the rolling distance of the tire, and it decreases rapidly as the traveling distance becomes longer.

  The required turning torque when starting from a state where the vehicle is stopped at the maximum rudder angle is equal to or less than the maximum torque T1 of the steering motor 9, and the travel distance that can be steered by the steering motor 9 is L1. To do. In this embodiment, when starting from a state where the vehicle is stopped while being steered, the electromagnetic clutch 7 is released to separate the steering shaft 6 and the steered shaft 4 when the travel distance becomes L1, and FIG. As shown, the steering motor 9 is controlled so that the rack stroke with respect to the steering operation angle becomes an ideal characteristic. Although FIG. 6 shows a positive rack stroke with respect to a positive operation angle, the rack stroke with respect to a negative operation angle is the same except that the polarity is negative, and the illustration is omitted.

  Note that the travel distance L1 is about 50 mm, and the driver's sense of turning the vehicle is slow at low speeds. Also, as described above, there are many operations in the vicinity of the maximum operating angle, so that the steering gain It is considered that even if the steering motor 9 forcibly performs correction so as to match the ideal characteristic gain, the driver does not feel uncomfortable.

  FIG. 7 shows the characteristic of the steering reaction force with respect to the steering operation angle at the time of stationary. 7 shows a positive operation reaction force with respect to a positive operation angle, the operation reaction force with respect to a negative operation angle is the same except that the polarity is negative, and the illustration is omitted.

  Regardless of whether the steering shaft 6 and the steering shaft 4 are connected or disconnected, the steering motor 9 and the reaction force are adjusted so that the steering operation reaction force with respect to the steering operation angle becomes the smoothly changing target operation reaction force shown in the figure. The generation motor 12 is controlled.

  Since the steering shaft 6 and the steered shaft 4 are separated up to the steering operation angle S1, the operation resistance generator 13 and the reaction force generation motor 12 are used for the steering operation angle according to the target operation reaction force shown in FIG. Generate reaction force.

  On the other hand, at the operation angle S1 or more after the shaft connection, the resistance force of the steering mechanism 1 including the tire suddenly increases as shown in FIG. 7, so that the steering wheel suddenly becomes “heavy” during the steering operation. Give a strange feeling. Therefore, in this embodiment, after the shaft is connected, a driving force that is a difference between the target operation reaction force and the resistance force is generated from the steering motor 9 and the reaction force generating motor 12, and the reaction force against the steering operation is also maintained after the shaft connection. The force is changed according to the target operation reaction force. Accordingly, the reaction force against the steering operation smoothly changes along the target operation reaction force from the shaft separation state to the shaft connection state.

  When the steering operation angle exceeds the predetermined value S2, the difference between the target operation reaction force and the resistance force exceeds the driving force of the steering motor 9, so that the reaction force is generated from the operation angle S2 to the maximum operation angle. A driving force is also generated from the motor 12. In other words, the output capacity of the steering motor 9 can be further reduced by the amount by which the driving force is generated from the reaction force generating motor 12, and the installation space and the vehicle weight can be reduced.

  FIG. 8 shows drive torque characteristics of the steering motor 9 and the reaction force generation motor 12 with respect to the steering operation angle at the time of stationary. Although FIG. 8 shows the driving torque and reaction force torque with respect to the positive operating angle, the driving torque and reaction force torque with respect to the negative operating angle are the same except that the polarities are opposite, and the illustration is omitted.

  Since the steering shaft 6 and the steered shaft 4 are separated up to the steering operation angle S1, the steering mechanism 1 is driven by generating a driving torque from the steering motor 9, and the target operation is performed from the reaction force generating motor 12. A reaction torque corresponding to the reaction force is generated. When the shaft is separated, the driving torque of the steering motor 9 increases as the steering operation angle increases, and reaches the maximum torque at the operation angle S1. Further, the reaction force torque of the reaction force generation motor 12 increases as the steering operation angle increases.

  In the range of the steering operation angle from S1 to S2, as described above, in order to output the driving torque corresponding to the difference between the resistance force of the steering mechanism 1 and the target operation reaction force from the steering motor 9, the operation angle S1. , The driving torque is once reduced, and then the driving torque is increased in accordance with the increase in the difference, and reaches the maximum torque at the operation angle S2. On the other hand, the operation reaction force motor 12 sets the output torque to 0 in the range of the operation angles S1 to S2.

  When the steering operation angle is S2 or more, even if the steering motor 9 outputs the maximum torque, the difference between the resistance force of the steering mechanism 1 and the target operation reaction force cannot be fully borne. The driving torque is also output, and the driving torque corresponding to the above difference is output by the steering motor 9 and the reaction force generation motor 12.

  9 to 11 are flowcharts showing the steering control program. The operation of the embodiment will be described with reference to these flowcharts. The microcomputer of the controller 15 starts executing the steering control program when an ignition key switch (not shown) is turned on.

  In step 1, it is confirmed by the vehicle speed sensor 16 whether the vehicle speed is substantially zero, that is, whether the vehicle is stopped. If the vehicle is stopped, the process proceeds to step 2, and the operation angle sensor 14 checks whether or not the steering operation angle is in the range of −S1 or more and + S1 or less. If the operation angle is in the range of −S1 or more and + S1 or less, the process proceeds to step 3; otherwise, the process proceeds to step 6.

  When the vehicle is stopped and the steering operation angle is −S1 or more and + S1 or less, the electromagnetic clutch 7 is released in step 3 to separate the steering shaft 6 and the steered shaft 4. In the following step 4, the steering motor 9 is controlled so that the rack stroke becomes the characteristic 1 shown in FIG. 4 according to the steering operation angle, and the steering mechanism 1 is driven by the steering motor 9 to perform the steering. . Further, in step 5, the reaction force generation motor 12 is controlled so that the steering operation reaction force becomes the target operation reaction force corresponding to the operation angle shown in FIG. 7, and reaction force torque is generated from the reaction force generation motor 12. . Then, it returns to step 1.

  When the vehicle is stopped and the steering operation angle is smaller than -S1 or larger than + S1, the electromagnetic clutch 7 is connected in step 6 to connect the steering shaft 6 and the steered shaft 4. In the following step 7, the steering motor 9 and the reaction force generating motor 12 are controlled, and the driving force corresponding to the difference between the resistance force of the steering mechanism 1 shown in FIG. Is generated. At this time, the steering motor 9 and the reaction force generation motor 12 generate a drive torque and a reaction force torque corresponding to the steering operation angle shown in FIG. Then, it returns to step 1.

  If the vehicle speed is not substantially zero and the vehicle is running, it is checked in step 11 whether the electromagnetic clutch 7 is connected and the steering shaft 6 and the steered shaft 4 are connected. If both shafts are connected, the process proceeds to step 12; otherwise, the process proceeds to step 21.

  If the vehicle is in a traveling state and the steering shaft 6 and the steered shaft 4 are already connected, it is confirmed in step 12 whether the traveling distance from the stopped state is within L1. Since the vehicle speed sensor 16 generates a vehicle speed pulse signal for every predetermined travel distance, the vehicle speed pulse is counted to detect the travel distance. If the travel distance from the stop state is within L1, the process proceeds to step 7, and if not, the process proceeds to step 13.

  When the travel distance from the stop state is within L1, in step 7, as described above, the steering motor 9 and the reaction force generating motor 12 are controlled, and the steering mechanism shown in FIG. A driving force corresponding to the difference between the resistance force 1 and the target operation reaction force is generated. At this time, the steering motor 9 and the reaction force generation motor 12 generate a drive torque and a reaction force torque corresponding to the steering operation angle shown in FIG. Then, it returns to step 1.

  On the other hand, when the travel distance from the stop state exceeds L1, it is determined in step 13 that the steering can be performed only by the steering motor 9, the electromagnetic clutch 7 is released, and the steering shaft 6 and the steering shaft 4 are separated. . In the following step 14, the steering motor 9 is controlled so that the rack stroke has the ideal characteristics shown in FIG. 6 according to the steering operation angle, and the steering mechanism 1 is driven by the steering motor 9 to perform the steering. . Further, in step 15, the reaction force generation motor 12 is controlled so as to obtain a target operation reaction force corresponding to the steering operation angle shown in FIG. Then, it returns to step 1.

  When the vehicle is in a traveling state and the steering shaft 6 and the steered shaft 4 are already separated, in step 21, the steered angle is obtained by multiplying the steering operation angle by the steering gain shown in FIG. The motor 9 is controlled, and the steering mechanism 1 is driven by the steering motor 9 to perform the steering. In the subsequent step 22, the reaction force generation motor 12 is controlled so as to obtain the operation reaction force shown in FIG. 7 according to the steering operation angle, thereby generating reaction force torque.

  In step 23, a deviation between the target steering angle obtained by multiplying the steering operation angle detected by the operation angle detection sensor 14 by the steering gain and the actual steering angle detected by the steering angle detection sensor 10 is obtained. It is checked whether the deviation is equal to or greater than a predetermined value. If the steering angle deviation is greater than or equal to a predetermined value, it is determined that there is some failure in the steering device, and the routine proceeds to step 24 where the electromagnetic clutch 7 is connected. That is, the steering shaft 6 and the steered shaft 4 are directly connected to perform steering directly by the driver's steering operation. At this time, the driver is warned of the failure of the steering device by the display and the speaker. On the other hand, when the steering angle deviation is less than the predetermined value, the process returns to step 1 and the above-described processing is repeated.

<< Modification of Embodiment of Invention >>
In the above-described embodiment, an example in which the steering wheel 5 is used as the driver's operation means has been described. However, a joystick may be used as the driver's operation means.

FIG. 12 shows a configuration of a modified example using a joystick. In addition, the same code | symbol is attached | subjected to the apparatus similar to the apparatus shown in FIG. 1, and description is abbreviate | omitted.
A joystick 17 is connected to the steering shaft 6, and the wheel 2 can be steered left and right by tilting the joystick 17 left and right. The length of the joystick 17 is a length that can be steered by the driver. The operable range of the joystick 17 is within 180 degrees above the horizontal plane, that is, within ± 90 degrees with respect to the steering neutral position where the joystick 17 is vertical. When the joystick 17 is used, the reaction force generation motor 12 and the operation angle detection sensor 14 are directly connected to the steering shaft 6.

  Even if the joystick 17 is used instead of the steering wheel 5, the same effect as that of the above-described embodiment can be obtained.

<< Other Modifications of One Embodiment of the Invention >>
Another modification in which a steering motor is provided in the steering rack and a push / pull wire is used instead of the steering shaft will be described.

FIG. 13 shows the configuration of another modification. In addition, the same code | symbol is attached | subjected to the apparatus similar to the apparatus shown in FIG. 1, and description is abbreviate | omitted.
In this modification, the steering motor 9 and the steering angle detection sensor 10 described above are installed in the steering rack 18 a of the steering mechanism 18, and a push / pull wire 19 is used instead of the steering shaft 4. The push-pull wire 19 is composed of two deformable metal wires for right and left pulling, one end of the wire 19 is connected to a disk 20 directly connected to the output shaft of the electromagnetic clutch 7 and the other end is connected. Connected to the steering rack 18a.

  Even if the steering motor 9 is provided in the steering rack 18a and the push / pull wire 19 is used instead of the steering shaft 4, the same effects as those of the above-described embodiment can be obtained. Further, in this modified example, the deformable push-pull wire 19 is used instead of the steered shaft 4, so that the degree of freedom of layout in the vehicle interior can be increased, and the steering shaft 6 is connected to the steering mechanism 18. Since it is not rigidly connected, it is possible to increase the shock absorption capacity of the steering wheel during a collision.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the steering wheel 5 is the operating means, the operating angle detecting sensor 14 is the operating angle detecting means, the steering motor 9 is the steering driving means, the steering angle detecting sensor 10 is the steering angle detecting means, The pull wire 19 constitutes a wire means, the electromagnetic clutch 7 constitutes an intermittent means, and the controller 15 constitutes a control means. The above description is merely an example, and when interpreting the invention, the correspondence between the items described in the above embodiment and the items described in the claims is not limited or restricted.

It is a figure which shows the structure of one embodiment. It is a figure which shows the steering gain with respect to a vehicle speed. It is a figure which shows the stationary required torque with respect to a rack stroke. It is a figure which shows the rack stroke with respect to the steering operation angle at the time of a stationary operation. It is a figure which shows the steering required torque with respect to the travel distance from a stop state. It is a figure which shows the rack stroke with respect to a steering operation angle when it starts from the state which steered and stopped. It is a figure which shows the operation reaction force of the steering with respect to a steering operation angle. It is a figure which shows the drive torque of the motor for steering with respect to a steering operation angle, and the motor for reaction force generation | occurrence | production. It is a flowchart which shows the steering control program of one Embodiment. FIG. 10 is a flowchart illustrating the steering control program according to the embodiment following FIG. 9. FIG. It is a flowchart which shows the steering control program of one Embodiment following FIG. It is a figure which shows the structure of the modification of one Embodiment. It is a figure which shows the structure of the other modification of one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering mechanism 2 Wheel 3 Pinion 4 Steering shaft 5 Steering wheel 6 Steering shaft 7 Electromagnetic clutch 8 Worm gear 9 Steering motor 10 Steering angle detection sensor 11 Worm gear 12 Reaction force generation motor 13 Operation resistance generator 14 Operation angle detection Sensor 15 Controller 16 Vehicle speed sensor 17 Joystick 18 Steering mechanism 18a Steering rack 19 Push-pull wire 20 Disc

Claims (6)

Operating means for the driver to steer;
An operation angle detection means for detecting an operation angle of the operation means;
A steering mechanism connected to the wheels;
Deformable wire means connected to the steering mechanism;
A steering drive means for steering the wheels by driving the steering mechanism,
Rudder angle detecting means for detecting the rudder angle of the wheel;
The input side is connected to the operation means, and the output side is connected to the deformable wire means, and the operation means and the steering mechanism are connected and disconnected via the wire means (hereinafter simply referred to as shaft connection and shaft disconnection). Shaft interruption means for performing
Control means for controlling the steering drive means and the shaft intermittent means,
The control means controls the steering drive means so that the steering angle detection value becomes a target steering angle corresponding to the operation angle detection value when the shaft is disconnected, and after the shaft is connected, A steering apparatus for a vehicle, wherein the steering mechanism is driven using an operating force as a driving force for driving the steering mechanism. The vehicle steering apparatus according to claim 1,
A vehicle steering apparatus characterized in that a push-pull wire composed of two wires for right and left pulling is used as the wire means. The vehicle steering apparatus according to claim 2 ,
A vehicle steering apparatus , wherein a disk is connected to an output shaft of the shaft interrupting means, and one end of the push-pull wire is connected to the disk so as to be connected to the output shaft of the shaft interrupting means . The vehicle steering apparatus according to any one of claims 1 to 3 ,
A vehicle steering apparatus, wherein a deformable metal wire is used as the wire means . In the vehicle steering device according to any one of claims 1 to 4,
A vehicle steering apparatus characterized in that, when a failure occurs in the steering apparatus, the shaft is connected by the shaft interrupting means . In the vehicle steering device according to any one of claims 1 to 5,
The control device drives the steering mechanism by adding the driving force of the steering driving device to the operation force after the shaft is connected .

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