JP2003267249A - Steering device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely perform the engagement operation of an engagement/ disengagement means between a steering means and a steering mechanism even when the voltage of an in-vehicle power supply is suddenly dropped. <P>SOLUTION: An electromagnetic clutch 4 for engaging and disengaging a transmission shaft 16 rotated interlocking with the operation of the steering mechanism 1 with and from a column shaft 20 rotating according to the operation of a steering wheel 2 is installed between the transmission shaft 16 and the column shaft 20. An engagement and disengagement control part 5 for controllably engaging and disengaging the electromagnetic clutch 4 is formed so as to be operated at a voltage sufficiently lower than the future output voltage of the in-vehicle power supply 6 used as a power supply. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system for steering a vehicle in response to an operation of a steering means such as a steering wheel performed by a driver.

[0002]

2. Description of the Related Art Steering of a vehicle is performed by operating a steering means (generally, a steering wheel rotating operation) performed by a driver inside a passenger compartment, and manipulating a steering wheel (generally a front wheel). This is done by telling the steering mechanism that is arranged outside the vehicle compartment for direction.

As such a vehicle steering system, in recent years,
The steering means inside the vehicle compartment is mechanically separated from the steering mechanism outside the vehicle compartment, and a steering actuator is attached to a part of the steering mechanism. A separate steering device, a so-called steer-by-wire steering device, configured to operate based on the detection result of the operation amount and to apply steering force to the steering mechanism to perform steering according to the operation of the steering means is provided. Proposed.

In this type of steering apparatus, the correspondence relationship between the operation amount of the steering means and the operation amount of the steering actuator can be freely set without any mechanical restriction, and the vehicle speed can be increased or decreased.
It has an advantage that it is possible to flexibly respond to the control of changing the steering characteristics according to the traveling state such as the degree of turning and the presence / absence of acceleration / deceleration. An electric motor is generally used as the steering actuator in consideration of easiness of control for changing steering characteristics.

On the other hand, in such a separate type steering device, various sensors for detecting the traveling state of the vehicle including the steering actuator, the operating direction and the operating amount of the steering means,
In addition, it is important to take fail-safe measures for the steering control unit that controls the steering actuator based on the detection results of these sensors. Conventionally, while the steering actuator, the sensor, and the steering control unit have a dual system, A drive connecting means such as an electromagnetic clutch is interposed between an input side member that rotates according to the operation of the means and an output side member that rotates according to the operation of the steering mechanism, and this drive connecting means is used when a failure occurs. The connecting operation is performed so that the operating force of the steering means can be mechanically transmitted to the steering mechanism, and manual steering can be performed.

[0006]

The connecting operation of the drive connecting means is a fail which may interfere with the operation control of the steering actuator while the steering control section is executing the operation control. The state is determined, and a connection command is issued to the drive connection means based on the result of this determination.

The fail state which is the object of the judgment is
With the abnormality of the steering actuator, the sensor, and the steering control unit itself, including the steering control unit and the steering actuator, there is a voltage drop of the vehicle-mounted power supply provided for supplying power to various electric devices equipped in the vehicle, If this voltage drop occurs, the operation of the steering control unit and the steering actuator will be hindered, so it is necessary to connect the drive connecting means.

However, the on-vehicle power source is generally composed of an on-vehicle battery and an alternator driven by an engine. The periphery of the alternator, that is, the alternator itself, the engine serving as a drive source, or transmission between the two. If any malfunction occurs in the system, a sudden voltage drop will occur, and in the steering control unit operated by the power supply from such an on-vehicle power supply, a fail judgment based on the voltage drop is made, and this fail judgment is made. Accordingly, the fail-safe operation for connecting the drive connecting means may be difficult.

The present invention has been made in view of the above circumstances, and ensures the connecting operation of the drive connecting means between the steering means and the steering mechanism even when a sudden voltage drop occurs in the vehicle-mounted power source. It is an object of the present invention to provide a vehicle steering device that does not hinder the fail-safe operation for shifting to manual steering.

[0010]

A vehicle steering system according to a first aspect of the present invention includes an input side member that rotates in response to an operation of the steering means, and an output side member that rotates in conjunction with the operation of a steering mechanism. In a vehicle steering system including a drive connecting means for driving and connecting both members, and a connection control section connected to an in-vehicle power supply for connecting and controlling the drive connecting means, a voltage detecting means for detecting an output voltage of the in-vehicle power supply. And a determination unit that determines whether the detection voltage of the voltage detection unit is lower than a predetermined lower limit voltage, the connection control unit, under the supply of a voltage lower than the lower limit voltage, It is characterized in that the drive connecting means can be connected according to the judgment of the judging means.

According to the present invention, when the output voltage of the on-vehicle power supply detected by the voltage detecting means becomes lower than the lower limit voltage and there is a possibility that the operation of the steering mechanism is hindered, the output voltage is lower than the lower limit voltage. By the operation of the connection control unit under the supply of a low voltage, the drive connection means for drivingly connecting the input side member and the output side member is connected, and the shift to the manual steering is surely performed.

A vehicle steering system according to a second aspect of the present invention includes an input side member that rotates in response to an operation of the steering means, an output side member that rotates in conjunction with the operation of the steering mechanism, and a drive connection between both members. In a vehicle steering system comprising: a drive connecting means for connecting and a connection control section for connecting and controlling the drive connecting means,
The connection control includes: voltage detection means for detecting an output voltage of a vehicle-mounted power supply mounted on the vehicle; and determination means for determining whether or not the detection voltage of the voltage detection means is lower than a predetermined lower limit voltage. The section is connected to a power source different from the vehicle-mounted power source, and is configured such that the drive coupling means can be coupled in accordance with the determination of the determination means.

According to the present invention, when the output voltage of the on-vehicle power source detected by the voltage detecting means becomes lower than the lower limit voltage and there is a possibility that the operation of the steering mechanism is hindered, it differs from the on-vehicle power source. By the operation of the connection control unit connected to the power source, the drive connection means for drivingly connecting the input side member and the output side member is connected, and the shift to the manual steering is surely performed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic block diagram showing a first embodiment of a vehicle steering system according to the present invention.

The illustrated vehicle steering system includes a steering mechanism 1 for causing a pair of steering wheels 10, 10 arranged on the left and right sides of a vehicle body to perform a steering operation, and a steering mechanism 1 from the steering mechanism 1. And a steering wheel (steering means) 2 that is rotationally operated for steering, and is configured as a separate steering device. To realize steering according to the operation of the steering wheel 2. A steering control unit 3 that performs a steering control operation that controls the steering motor M ₁ and a reaction force control operation that controls the reaction force motor M ₂ to apply an appropriate steering reaction force to the steering wheel 2, and will be described later when various failures occur. And a coupling control unit 5 that controls the coupling of the electromagnetic clutch 4.

In the vehicle steering system shown in the drawing, the steering control section 3 and the connection control section 5 are connected to an on-vehicle power source 6 mounted on the vehicle, and each control operation is performed by power supply from the on-vehicle power source 6. Yes. The vehicle-mounted power source 6 is composed of a vehicle-mounted battery and an alternator driven by an engine, and the connection control unit 5 can operate under a voltage lower than that of the steering control unit 3, and the operating voltage is It is set to be equal to or lower than the output voltage of the on-vehicle battery alone.

The steering mechanism 1 is a well-known rack and pinion type steering mechanism, in which both ends of a rack shaft 11 extending in the left-right direction of the vehicle body and moving in the axial direction are provided with steering wheels. Ten,
The knuckle arms 12, 12 are connected to the knuckle arms 12, 12 via the respective tie rods 13, 13 and the knuckle arms 12, 12 are pushed and pulled through the tie rods 13, 13 by the movement of the rack shaft 11 in both directions. , 10 is steered left and right.

In order to perform this steering, a steering motor M ₁ as a steering actuator is attached to the outside of the middle of a tubular rack housing H ₁ that supports the rack shaft 11 movably in the axial direction. ing. The output shaft of the steering motor M ₁ extends inside the rack housing H ₁ and is configured to be transmitted to the middle of the rack shaft 11 via a motion conversion mechanism such as a ball screw mechanism. When the steering motor M ₁ is rotationally driven, the rotation is converted into the movement of the rack shaft 11 in the axial direction by the motion conversion mechanism, and the steering described above is performed according to the movement.

Further, a pinion housing H ₂ is continuously provided at a midway portion of the rack housing H ₁ away from the mounting position of the steering motor M ₁ so as to intersect with this, and the inside of the pinion housing H ₂ A pinion shaft 14 is rotatably supported on the pinion shaft 14. A pinion (not shown) is integrally formed on the lower half portion of the pinion shaft 14 located inside the pinion housing H ₂ , and is formed at a corresponding portion of the rack shaft 11 at an intersection with the rack housing H _1. Not meshed with rack teeth.

A transmission shaft 16 is connected to the upper end of the pinion shaft 14 protruding above the pinion housing H ₂ via a universal joint 15a, an intermediate shaft 15b and a universal joint 15c. The transmission shaft 16 is rotatably supported about its axis and extends upward toward the position where the steering wheel 2 is disposed.

With the above construction, when the rack shaft 11 moves in the axial direction for steering, this movement is converted into rotation around the pinion shaft 14 at the meshing portion of the rack teeth and the pinion. The rotation is transmitted to the transmission shaft 16 via the universal joint 15a, the intermediate shaft 15b, and the universal joint 15c. As a result, the transmission shaft 16 moves with the movement of the rack shaft 11, that is, the operation of the steering mechanism 1. Rotate around the axis. Conversely, when a rotational force is applied to the transmission shaft 16, the universal joint 15c, the intermediate shaft 1
5b, pinion shaft 14 via universal joint 15a
Is applied to the rack shaft 11, which is subjected to motion conversion in the meshing portion of the pinion and the rack tooth, and a moving force in the axial direction is applied to the rack shaft 11 on which the rack tooth is formed.

The steering motor M ₁ includes the steering control unit 3
Drive control is performed in accordance with an operation command given to a drive circuit (not shown). The actual steering angle of the steering wheels 10, 10 steered according to this drive is the rack shaft 11 and the tie rod on one side.
It is detected by an actual steering angle sensor 17 configured to detect the displacement of the connection portion with 13, and is provided to the steering control unit 3. Further, a tie rod axial force sensor (reaction force sensor) 18 for detecting an axial force acting in the axial direction is attached to the tie rod 13 on one side, and the detection result indicates the steering mechanism 1 in association with steering.
It is given to the steering control unit 3 as a signal indicating the steering reaction force actually applied to the steering control unit 3.

The steering wheel 2 which is arranged separately from the steering mechanism 1 as described above has a column housing H ₃ rotatably supporting a column shaft 20 which is a rotation shaft thereof, so that the steering wheel 2 can be appropriately mounted on a vehicle body (not shown). It is supported by the site.
A reaction force motor M ₂ that is rotationally driven to apply a steering reaction force to the steering wheel ₂ is attached to a middle portion of the column housing H ₃ . The output shaft of the reaction force motor M ₂ is extended inside the column housing H _3, which is a transmission configured in the middle portion of the column shaft 20 through the reduction mechanism such as a worm gear mechanism, the reaction motor M ₂ When rotationally driven, this rotational force is applied to the column shaft 20 under deceleration by the reduction mechanism, and a steering reaction force is applied to the steering wheel 2 fixed to the upper end of the column shaft 20.

The reaction force motor M ₂ is driven according to an operation command given from the steering control section 3 to a drive circuit (not shown), and the steering control section 3 is driven by the steering wheel 2.
In order to give an appropriate steering reaction force to the engine, a reaction force control operation for increasing or decreasing the drive current of the reaction force motor M ₂ is performed.

The operating angle of the steering wheel 2 which is rotated against the steering reaction force is determined by the column housing H ₃
It is detected by the steering angle sensor 21 attached to the middle part of the
It is provided to the steering control unit 3. Further, the steering control unit 3 is provided with a detection result of a traveling state such as a vehicle speed, a yaw rate, a lateral acceleration, and a longitudinal acceleration, which influences steering, from a traveling state sensor 22 installed in each part of the vehicle.

The column shaft 20, which is the rotating shaft of the steering wheel 2, is projected below the column housing H _{3 by} an appropriate length, and is abutted against the upper end of the transmission shaft 16.
A column shaft 20 (input side member) that rotates in response to an operation of the steering wheel 2 and a transmission shaft 16 (output side member) that rotates as described above in accordance with the operation of the steering mechanism 1 are provided in this butting portion. An electromagnetic clutch 4 that is drivingly connected is configured.

The electromagnetic clutch 4 is a well-known drive connecting means for connecting and operating in accordance with an operation command given from the connection control section 5 to an exciting circuit (not shown). The electromagnetic clutch 4
Is in a connected state, the transmission shaft 16 and the column shaft 20 are mechanically connected, and the rotation of the column shaft 20 according to the rotating operation of the steering wheel 2 is transmitted to the transmission shaft 16 via the electromagnetic clutch 4. , Further, universal joint 15c,
Mechanical force from the steering wheel 2 to the steering mechanism 1 is transmitted as a result of being transmitted to the rack shaft 11 via the intermediate shaft 15b, the universal joint 15a and the pinion shaft 14 and applying a moving force in the axial direction to the rack shaft 11. It becomes possible to perform manual steering by various transmissions.

A fail signal, which will be described later, is given to the connection control unit 5 from the steering control unit 3, and a voltage detector 60 attached to the vehicle-mounted power supply 6 serving as a power source for the steering control unit 3 and the connection control unit 5 outputs the signal. The detection result of the output voltage of the in-vehicle power supply 6 is given, and the connection control operation of the connection control unit 5 is performed based on the fail signal and the detection voltage of the voltage detector 60 as described later. There is.

The steering control operation of the steering control section 3 for the steering motor M ₁ is performed by, for example, multiplying the operating angle of the steering wheel 2 detected by the steering angle sensor 21 by a predetermined control gain. This target steering angle and the left and right front wheels 1 detected by the actual steering angle sensor 17 are obtained.
Feedback control is performed based on the deviation from the actual steering angle of 0 and 10.

At this time, the traveling state detected by the traveling state sensor 22 is used for selecting the control gain. This control gain decreases, for example, as the vehicle speed increases,
Further, it is set as a value that decreases with an increase in the degree of turning of the vehicle that is determined by the yaw rate and lateral acceleration. As a result, the target steering angle becomes small during high-speed traveling, becomes large during low-speed traveling, and becomes smaller during steered traveling as the vehicle makes a sharp turn, and the steering motor M ₁ based on such target steering angle becomes smaller. By the control, steering characteristics according to the traveling state can be obtained.

Further, in the above steering control operation, the dead zone is set near the neutral position of the steering wheel 2 and the steering motor is operated when the operation angle of the steering wheel 2 detected by the steering angle sensor 21 is within the dead zone. The drive of M ₁ is stopped. This allows
There is no risk that steering will be performed by the idle operation of the steering wheel 2 near the neutral position, and it is possible to prevent the occurrence of wobbling feeling when traveling straight ahead, and to suppress energy consumption due to unnecessary driving of the steering motor M _1. be able to.

In the reaction force control operation of the steering control section 3 for the reaction force motor M ₂ , for example, the actual reaction force applied to the steering mechanism 1 is obtained based on the input from the tie rod axial force sensor 18, The target reaction force to be applied to the steering wheel 2 is calculated by multiplying the obtained actual reaction force by a predetermined control gain, and the drive current corresponding to this target reaction force is applied to the reaction force motor M ₂
It will be done by supplying power to.

At this time, the traveling state detected by the traveling state sensor 22 is used to correct the control gain. This correction is performed, for example, such that the control gain increases as the vehicle speed and the turning degree increase, and the control gain increases as the deceleration degree obtained by the longitudinal acceleration increases. Further, the operation angle of the steering wheel 2 detected by the steering angle sensor 21 can be used for the correction of the actual reaction force to change the increase characteristic of the drive current of the reaction force motor M ₂ .

By the above reaction force control operation, the rotational force of the reaction force motor M ₂ applied to the column shaft 20 is applied to the steering wheel 2 as a steering reaction force. The steering reaction force is obtained by correcting the actual reaction force applied to the steering mechanism 1 according to the traveling state, and allows the driver who operates the steering wheel 2 to experience a good steering feeling.

On the other hand, the connection control operation of the connection control unit 5 for the electromagnetic clutch 4 is performed according to the flowchart shown in FIG. The connection control unit 5 starts its operation by supplying power from the vehicle-mounted power supply 6 in response to an ON operation of a key switch (not shown), and first checks whether or not a fail signal is input from the steering control unit 3 (step 1), When it is determined that there is a fail signal, the process proceeds to step 4, where a connection command is issued to the electromagnetic clutch 4, and the electromagnetic clutch 4 is connected.

During execution of the steering control and the reaction force control performed as described above, the steering control section 3 receives each sensor on the input side, the steering motor M ₁ and the reaction force motor M ₂ on the output side, and
An abnormality diagnosis is performed for the steering control unit 3 itself, and if it is determined that an abnormality has occurred in any of the results of this abnormality diagnosis, erroneous steering control and reaction force control under this abnormality are stopped. At the same time, the fail signal is issued.

The connection operation of the electromagnetic clutch 4 performed in step 4 in response to such a fail signal connects the transmission shaft 16 and the column shaft 20 as described above, and operates the steering operation of the steering wheel 2 by a steering mechanism. In order to enable emergency steering at the time of stopping steering control and reaction force control by manual steering by mechanical transmission.

On the other hand, when it is determined in step 1 that there is no fail signal, the connection control section 5 then takes in the detection voltage V of the voltage detector 60 applied to the input side (step 2), and this detection voltage is detected. V, that is, the output voltage of the vehicle-mounted power source 6 that is the power source of the steering control unit 3 and the connection control unit 5 is compared with a preset lower limit voltage V _min (step 3).

The lower limit voltage V _min is determined by the steering control unit 3
Is the lowest voltage value that enables normal operation, and as a result of the comparison in step 3, the current detected voltage V is the lower limit voltage V.
_{If it is min} or more, the connection control unit 5 determines that the steering control unit 3
It is determined that the steering control and the reaction force control operation are normally performed, the process returns to step 1 without performing any control operation, and the above-described operation is repeated.

On the other hand, as a result of the comparison in step 3, when the current detected voltage V is less than the lower limit voltage V _min , the connection control unit 5 disables the steering control unit 3 due to the voltage drop of the vehicle-mounted power supply 6. It is determined that the electromagnetic clutch 4 may be reached, and a connection command is issued to the electromagnetic clutch 4 to perform an operation to connect the electromagnetic clutch 4 (step 4).

When the electromagnetic clutch 4 is connected, as described above, the transmission shaft 16 and the column shaft 20 are connected, the rotational operation of the steering wheel 2 is transmitted to the steering mechanism 1, and the steering control unit 3 cannot operate. Emergency steering can be performed by manual steering by mechanical transmission.

The decrease in the output voltage of the on-vehicle power supply 6 should be one of the items of abnormality diagnosis which is originally performed in the steering control section 3. However, as described above, the vehicle-mounted power source 6 is composed of the vehicle-mounted battery and the alternator, and when a problem occurs in the vicinity of the alternator, the output voltage of the vehicle-mounted power source 6 sharply decreases and the inside of the steering control unit 3 is reduced. There is a possibility that the determination of the voltage drop and the engagement operation of the electromagnetic clutch 4 according to this determination may not be performed.

In the present invention, the determination of the voltage drop of the on-vehicle power source 6 and the engagement operation of the electromagnetic clutch 4 according to this determination are performed by the engagement control unit 5 independent of the steering control unit 3. As described above, the connection control unit 5 uses the steering control unit 3
The operating voltage is set to be lower than the output voltage of the in-vehicle battery that constitutes the in-vehicle power source 6 alone, so that even if a failure occurs in the alternator. , Determination of the voltage drop,
Also, the engaging operation of the electromagnetic clutch 4 according to this determination can be reliably performed.

When the electromagnetic clutch 4 is engaged in step 4, the steering feeling experienced by the driver who operates the steering wheel 2 changes greatly. Therefore, the engagement control section 5 causes the engagement operation of the electromagnetic clutch 4. In parallel with the above, an alarm operation such as sounding an alarm sound and generation of a voice message is performed to notify the driver that the steering feeling is changed, and the vehicle is placed on the road shoulder while carefully operating the steering wheel 2. It is desirable to urge them to approach the vehicle by stopping it.

FIG. 3 is a schematic block diagram showing a second embodiment of the vehicle steering system according to the present invention. The vehicle steering system shown in this figure is similar to the vehicle steering system shown in FIG. 1, and a steering mechanism 1 for causing the steering wheels 10 and 10 to perform a steering operation, and a steering mechanism 1 The steering device is configured as a separate type steering device including a steering wheel 2 that is mechanically separated, and a steering control operation that targets the steering motor M ₁ and a reaction force that targets the reaction force motor M _2. A steering control unit 3 that performs a control operation and a connection control unit 5 that performs a connection control operation of the electromagnetic clutch 4 when a failure occurs are provided.

The difference between the vehicle steering system shown in this figure and the vehicle steering system shown in FIG.
While the steering control operation and the reaction force control operation are performed by the power supply from the connection control unit 5, the connection control unit 5 is connected to the control power supply 7 that is configured separately from the vehicle-mounted power supply 6.
The connection control operation is performed by supplying power from the control power supply 7. The configuration and operation of other parts are
The steering control operation and the reaction force control operation of the steering control section 3 and the connection control operation of the connection control section 5 according to the flowchart shown in FIG. 2 are the same as those of the embodiment shown in FIG. The same reference numerals as those in FIG. 1 are attached to the portions and the description thereof will be omitted.

Also in this embodiment, the determination of the voltage drop of the vehicle-mounted power source 6 and the engagement operation of the electromagnetic clutch 4 according to this determination are controlled by the engagement control unit 5 independent of the steering control unit 3, and this engagement is performed. The control unit 5 is configured to operate by the power supply from the control power supply 7 instead of the power supply from the vehicle-mounted power supply 6. Therefore, even if the voltage drop of the vehicle-mounted power source 6 suddenly occurs due to a malfunction of the alternator that constitutes the vehicle-mounted power source 6, the determination of the voltage drop and the engagement operation of the electromagnetic clutch 4 according to this determination can be reliably performed. Therefore, it is possible to reliably avoid the occurrence of steering failure due to the voltage drop.

In the above embodiment, the electric motor (steering motor M ₁ ) is used as the steering actuator that applies the steering force to the steering mechanism 1, but an actuator other than the electric motor may be used. Further, in the above embodiment, the electromagnetic clutch 4 is used as the drive connecting means for drivingly connecting the input side member and the output side member, but it goes without saying that other drive connecting means may be used.

Further, in the above embodiment, the application example to the separate type steering device in which the steering means and the steering mechanism are mechanically separated has been described, but the present invention is directed to the steering means and the steering mechanism. It is also applicable to a connecting type vehicle steering system including a transmission ratio variable mechanism that can change the ratio between the operation angle of the steering means and the steering angle of the steering mechanism. In this case, when the detected voltage of the voltage detecting means becomes lower than a predetermined lower limit voltage, the drive connecting means may perform the connecting operation to fix the ratio.

[0050]

As described in detail above, in the vehicle steering system according to the first aspect of the present invention, the connection control section for controlling the drive connection means for drive-connecting the steering means and the steering mechanism includes:
Since it operates at a voltage sufficiently lower than the original output voltage of the on-vehicle power supply, even if the output voltage of the on-vehicle power supply drops to such an extent that it interferes with steering, manual steering by connecting the drive connecting means is possible. Can be surely performed.

Further, in the vehicle steering system according to the second aspect of the present invention, the connection control section for controlling the drive connecting means for drivingly connecting the steering means and the steering mechanism is provided with a voltage supplied from a power source different from the vehicle-mounted power source. According to the present invention, even when the output voltage of the vehicle-mounted power source drops to such an extent that steering is hindered, the shift to manual steering can be reliably performed by connecting the drive connecting means. Has an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a first embodiment of a vehicle steering system according to the present invention.

FIG. 2 is a flowchart showing the content of an engagement / disengagement control operation of an electromagnetic clutch by a connection control unit.

FIG. 3 is a schematic block diagram showing a second embodiment of a vehicle steering system according to the invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Steering mechanism 2 Steering wheel (steering means) 3 Steering control section 4 Electromagnetic clutch (drive coupling means) 5 Coupling control section 6 Vehicle-mounted power supply 7 Control power supply 16 Transmission shaft (output side member) 20 Column shaft (input side member) 60 Voltage detector (voltage detection means) M ₁ steering motor M ₂ reaction motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B62D 137: 00 B62D 137: 00 F term (reference) 3D032 CC32 DA03 DA04 DA05 DA23 DA25 DA29 DA65 DB20 DC40 DD20 DE06 EB30 EC27 GG01 3D033 CA12 CA13 CA14 CA17 CA18 CA29 CA31

Claims (2)

[Claims] 1. An input-side member that rotates in response to an operation of a steering means, and an output-side member that rotates in association with the operation of a steering mechanism.
In a vehicle steering system comprising a drive connecting means for drivingly connecting both members, and a connection control section connected to an in-vehicle power source for connecting and controlling the drive connecting means, a voltage detecting means for detecting an output voltage of the in-vehicle power source, A determination unit that determines whether or not the detection voltage of the voltage detection unit is lower than a predetermined lower limit voltage, the connection control unit is configured to perform the determination when the voltage lower than the lower limit voltage is supplied. A steering apparatus for a vehicle, wherein the drive connecting means can be connected according to the determination of the means. 2. An input side member that rotates in response to an operation of the steering means, and an output side member that rotates in association with the operation of the steering mechanism.
In a vehicle steering system comprising a drive connecting means for drivingly connecting both members, and a connection control section for connecting and controlling the drive connecting means, a voltage detecting means for detecting an output voltage of an in-vehicle power source mounted on the vehicle, The connection control unit is connected to a power source different from the vehicle-mounted power source, and the determination unit determines whether or not the detection voltage of the voltage detection unit is lower than a predetermined lower limit voltage. Accordingly, the vehicle steering system is characterized in that the drive connecting means can be connected.