JPH10324263A - Steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a relationship between the steering amount of a steering handle and the steering amount of steering wheels even if an opposite input is made from a wheel side during traveling. SOLUTION: In a vehicular steering device having a variable gear ratio unit 14 provided for varying a transmission ratio by the driving of a motor in the midway of a steering transmission system for connecting a steering handle 10 and steering wheels 24, a connecting means is provided for stopping the operation of the variable gear ratio unit 14 by a signal from the outside and connecting the input side of the variable gear ratio unit 14 from the steering handle 10 with an output side to the steering wheels 24.

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 capable of changing a transmission ratio of a steering wheel steering angle to a steered wheel.

[0002]

2. Description of the Related Art Conventionally, as a steering device for varying a transmission ratio of a steering wheel steering angle to a steered wheel, there is a steering device disclosed in Japanese Patent Application Laid-Open No. 3-153467. This steering device includes a transmission ratio variable mechanism by a planetary gear type differential mechanism on a steering shaft between a steering handle and a pinion connected to a steered wheel.

[0003]

However, in this steering apparatus, since the variable transmission ratio mechanism is of a differential type, if an excessive reverse input is applied from the wheel side during traveling,
Due to this reverse input, the transmission ratio variable mechanism is moved, and the relationship between the steering amount of the steering wheel and the steering amount of the steered wheels may be shifted.

An object of the present invention is to provide a vehicular steering apparatus capable of maintaining a relationship between a steering amount of a steering wheel and a steering amount of a steered wheel even when a reverse input is made from a wheel during traveling. It is to be.

[0005]

According to a first aspect of the present invention, there is provided a vehicle steering system including a transmission ratio variable unit that varies a transmission ratio by driving a motor in a steering transmission system that connects a steering wheel and a steered wheel. In the vehicle steering system, the operation of the transmission ratio variable unit is stopped by an external signal, and the input side of the transmission ratio variable unit from the steering handle and the output side for the steered wheels are connected. It is characterized by comprising a connecting means.

According to the vehicle steering system of the first aspect, the input side and the output side of the transmission ratio variable unit are connected to each other in case of excessive reverse input or abnormality of the device, so that the transmission ratio variable unit is connected. , It is possible to steer directly, that is, with a fixed transmission ratio.

[0007] A vehicle steering system according to a second aspect of the present invention includes:
2. The vehicle transmission apparatus according to claim 1, wherein the transmission ratio variable means includes a motor therein, and a steering input of the steering handle is input to a housing of the motor, and a rotation shaft of the motor is connected to the steering wheel. An output is connected to a speed reducer, and the connecting means connects the housing and the rotating shaft.

According to the second aspect of the present invention, the motor housing and the rotary shaft are connected by the connecting means in case of excessive reverse input or abnormality of the apparatus, so that the transmission ratio variable means is not interposed. The steering can be performed directly, that is, with a fixed transmission ratio.

Further, the vehicle steering system according to claim 3 is
The transmission ratio varying means of the vehicle steering system according to the first aspect is a harmonic drive reduction gear, and the connecting means projects an engaging member into a gap between a circular spline and a flexspline.

According to the third aspect of the present invention, since the transmission ratio varying means is a harmonic drive reduction gear, the engagement member is interposed in the gap between the circular spline and the flex spline of the reduction gear to reduce the speed. By stopping the operation of the machine, the steering wheel and the steered wheels can be directly connected.

Further, the vehicle steering system according to claim 4 is
2. A drive unit provided in a housing of the motor, the connection unit of the vehicle steering system according to claim 1 being drivable in a direction parallel to an axis of the rotation shaft of the motor, and a connection expanded and contracted by the drive unit. And a connecting member, wherein the connecting member is extended by the driving means and connected to a rotating portion of the motor.

According to the fourth aspect of the present invention, since the motor housing and the rotating portion of the motor are increased and connected by the connecting member extended by the driving means, the amount of driving by the driving means is reduced. The driving means can be reduced in size.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A steering apparatus for a vehicle according to a first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a configuration diagram of the vehicle steering system 2. In the drawing, a reference numeral 10 denotes a steering handle, which is connected to an upper end of an upper steering shaft 12a. Also,
The lower end of the upper steering shaft 12a is connected to the variable gear ratio unit 14, and the upper end of the lower steering shaft 12b is connected to the variable gear ratio unit 14.

A pinion (not shown) is provided at a lower end of the lower steering shaft 12b, and the pinion is meshed with a rack bar 18 in the steering gear box 16. Further, one end of a tie rod 20 is connected to each end of the rack bar 18, and a steering wheel 24 is connected to the other end of each tie rod 20 via a knuckle arm 22.

A steering angle sensor 26 for detecting the steering angle of the steering handle 10 is provided on the upper steering shaft 12a.
b, an output angle sensor 3 for detecting the steering angle of the steered wheel 24;
0 is provided. The steering angle of the steering wheel 10 and the steering angle of the steering wheel 24 detected by the steering angle sensor 26 and the output angle sensor 30 are input to an ECU (electronic control device) 28. Further, a vehicle speed output from a vehicle speed sensor 32 that detects the vehicle speed is input to the ECU 28. On the other hand, the ECU 28 outputs a control signal for controlling the variable gear ratio unit 14 to the variable gear ratio unit 14.

Here, the variable gear ratio unit 14 corresponds to FIG.
As shown in FIG. 1, the motor 40 and the speed reducer 42 are provided. The motor 40 includes a stator 46 and a rotor 48 fixed in a motor housing 44, and the speed reducer 42 is configured as a speed reducer using a planetary gear mechanism. That is, the rotation of the rotating shaft 50 that rotates together with the rotor 48 is input to a sun gear (not shown) constituting the planetary gear mechanism, and the rotation of the carrier 52 is output as an output from the speed reducer 42.

A solenoid 56 for displacing the slide pin 54 in a direction parallel to the axis of the rotary shaft 50 is provided on the outer upper surface of the motor housing 44.
The solenoid 56 is driven by a control signal from the ECU 28, and displaces the slide pin 54 in a direction parallel to the axis of the rotating shaft 50 when a control signal is input from the ECU 28. Also, the upper surface 48 of the rotor 48
As shown in FIG. 3, a plurality of pin holes 48b into which the slide pins 54 are inserted are provided at substantially equal intervals circumferentially. That is, in the variable gear ratio unit 14, the slide pin 54, the solenoid 56, and the slide pin 54
The connecting means is constituted by the pin hole 48b into which the hole is inserted.

The motor housing 4 on the motor 40 side
4 is connected to the lower end of the upper steering shaft 12a via a universal joint (not shown), and the carrier 52 is connected to the upper end of the lower steering shaft 12b.

In the vehicle steering system 2, first,
When the vehicle speed detected by the vehicle speed sensor 32 and the steering angle detected by the steering angle sensor 26 are input to the ECU 28, the ECU 28 calculates a target steering angle based on the vehicle speed and the steering angle. A control signal based on the output is output to the variable gear ratio unit 14. Based on this control signal, the motor 40 of the variable gear ratio unit 14 is driven to give the steered wheels 24 a steering angle corresponding to the target steering angle.

In the vehicle steering system 2, the ECU
28 determines the presence or absence of a reverse input (kickback) from the steered wheels 24 side and determines the failure of the motor 40. That is, the steering wheel 1 detected by the steering angle sensor 26
When the deviation between the target steering angle obtained based on the steering angle of zero and the vehicle speed detected by the vehicle speed sensor 32 and the steering angle of the steered wheels 24 detected by the output angle sensor 30 is equal to or larger than a predetermined value, the steering is performed. It is determined that an excessive reverse input has been made from the side of the wheel 24, and the failure of the motor 40 is determined based on the current value supplied to the motor 40.

When the ECU 28 determines that there is an excessive reverse input from the steered wheels 24 and determines that the motor 40 has failed, it outputs a control signal to the solenoid 56 to switch the slide pin 54 It is displaced in a direction parallel to the axis of the rotating shaft 50. Thereby, the slide pin 54
Are pin holes 48b provided in the upper surface 48a of the rotor 48.
And the motor housing 44 and the rotor 48 are connected.

Accordingly, since the operation of the variable gear ratio unit 14 is stopped and the steering wheel 10 and the steered wheels 24 are directly connected, even if there is an excessive reverse input from the steered wheels 24, the reverse input is used. The occurrence of a phase shift can be prevented.

In addition, when the motor 40 fails, the steering wheel 10 and the steered wheels 24 are directly connected. Therefore, even if the motor 40 fails, steering with a fixed transmission ratio can be performed.

When the excessive reverse input from the steered wheels 24 has disappeared and the cause of the failure of the motor 40 has been eliminated, the ECU 28 outputs a control signal to the solenoid 56 to switch the slide pin 54. By pulling in, the connection between the steering wheel 10 and the steered wheels 24 is released. Thereby, the operation of the variable gear ratio unit 14 is restarted.

Next, a vehicle steering system according to a second embodiment of the present invention will be described with reference to FIGS. In this vehicle steering system, the variable gear ratio unit 14 of the vehicle steering system according to the first embodiment is changed to a variable gear ratio unit 60. In the description of the variable gear ratio unit 60 of the vehicle steering system according to the second embodiment, the same configuration as the configuration of the variable gear ratio unit 14 according to the first embodiment has the first configuration. The same reference numerals as those used in the description of the embodiments are used and the description is omitted.

Here, the variable gear ratio unit 60 is a motor 4 similar to the variable gear ratio unit 14 of the first embodiment.
0 and a speed reducer 42, and the connecting means is changed to an elliptical cam 62. That is, the upper surface 4 of the rotor 48
8a is provided with an elliptical cam 62 which rotates together with the rotation shaft 50.

In this vehicle steering system, the ECU 2
8 is the same as in the first embodiment, when it is determined that there is a reverse input from the steered wheels 24 and when it is determined that the motor 40 has failed, the control signal is output to the solenoid 56. To displace the slide pin 54 in a direction parallel to the axis of the rotation shaft 50. Thus, the slide pin 54 is inserted into a gap formed between the elliptical cam 62 and the motor housing 44.

In this state, the elliptical cam 62 together with the rotary shaft 50 is provided.
Rotates, the clearance formed between the elliptical cam 62 and the motor housing 44 shown in FIG.
And finally the motor housing 44 and the rotor 48
Are linked.

Therefore, the operation of the variable gear ratio unit 60 is stopped and the steering wheel 10 and the steered wheels 24 are directly connected. Therefore, even if an excessive reverse input is made from the steered wheels 24 side. It is possible to prevent the occurrence of a phase shift due to the reverse input.

Next, a vehicle steering system according to a third embodiment of the present invention will be described with reference to FIGS. This vehicle steering system is obtained by changing the variable gear ratio unit 14 of the vehicle steering system according to the first embodiment to a variable gear ratio unit 64. In the description of the variable gear ratio unit 64 of the vehicle steering system according to the third embodiment, the same configuration as the configuration of the variable gear ratio unit 14 according to the first embodiment has the first configuration. The same reference numerals as those used in the description of the embodiments are used and the description is omitted.

The variable gear ratio unit 64 is a motor 4 similar to the variable gear ratio unit 14 of the first embodiment.
0, and the speed reducer is constituted by a harmonic drive speed reducer 66. Here, the harmonic drive reducer 66 is composed of an elliptical cam and a ball bearing disposed on the outer periphery thereof, and is a wave generator 68 fixed to the rotating shaft 50, and is a flexible metal elastic body having teeth formed on the outer periphery. A deceleration constituted by a circular spline 72 which is a rigid body having a ring shape and fixed to the inner peripheral surfaces of the spline 70 and the motor housing 44 and has teeth at the same pitch as the flexspline 70 on the inner peripheral portion as a basic element Machine.

In this vehicle steering system, the ECU 2
8 is the same as in the first embodiment, when it is determined that there is a reverse input from the steered wheels 24 and when it is determined that the motor 40 has failed, the control signal is output to the solenoid 56. To displace the slide pin 54 in a direction parallel to the axis of the rotation shaft 50. Thereby, the slide pin 54 is inserted into a gap formed between the wave generator 68 and the circular spline 72.

When the wave generator 68 rotates together with the rotating shaft 50 in this state, the gap formed between the wave generator 68 and the circular spline 72 shown in FIG. The rotation shaft 50 is connected.

Accordingly, the operation of the variable gear ratio unit 64 is stopped and the steering wheel 10 is directly connected to the steered wheels 24. Therefore, even if a reverse input is made from the steered wheels 24, the reverse input is performed. Can prevent the occurrence of a phase shift.

Next, a vehicle steering system according to a fourth embodiment of the present invention will be described with reference to FIGS. This vehicle steering system is obtained by changing the variable gear ratio unit 14 of the vehicle steering system according to the first embodiment to a variable gear ratio unit 74. Note that, in the description of the variable gear ratio unit 74 of the vehicle steering system according to the fourth embodiment, the same configuration as the configuration of the variable gear ratio unit 14 according to the first embodiment has the first configuration. The same reference numerals as those used in the description of the embodiments are used and the description is omitted.

Here, the variable gear ratio unit 74 is a motor 4 similar to the variable gear ratio unit 14 of the first embodiment.
In this embodiment, the connecting means having a zero and a speed reducer 42 and using a link 76 having a pantograph structure is changed.
That is, as shown in FIG. 8, the connecting means supports two links 76 at the tip of the pin 54 driven by the solenoid 56 so that the tips of the two links 76 extend in the axial direction of the rotary shaft 50. It is constituted by the arranged spring member 78. In addition, unevenness is provided on the upper surface 48a of the rotor 48 to form a friction surface.

In this vehicle steering system, the ECU 2
8 is the same as in the first embodiment, when it is determined that there is a reverse input from the steered wheels 24 and when it is determined that the motor 40 has failed, the control signal is output to the solenoid 56. To displace the slide pin 54 in a direction parallel to the axis of the rotation shaft 50. As a result, the slide pins 54 extend the link members of the links 76, and the ends of the link members are pressed against the friction surfaces provided on the upper surface 48a of the rotor 48 as shown in FIG. Forty rotation shafts 50 are connected.

Accordingly, the operation of the variable gear ratio unit 74 is stopped and the steering wheel 10 is directly connected to the steered wheels 24. Therefore, even if an excessive reverse input is made from the steered wheels 24 side. It is possible to prevent the occurrence of a phase shift due to the reverse input. Further, in this connecting means, since the stroke of the pin 54 by the solenoid 56 is increased by the link 76 having a pantograph structure, it is not necessary to increase the displacement of the pin 54 by the solenoid 56 itself. can do.

In the variable gear ratio unit according to each of the above embodiments, the connecting means has a single pin 54 and the steering wheel 10 is directly connected to the steered wheels 24 by displacing this pin by the solenoid 56. Although the connecting means is provided with a plurality of pins, the steering handle and the steered wheels may be directly connected by displacing the pins with a solenoid. In this case, the direct connection between the steering wheel and the steered wheels can be performed more reliably than in the above-described embodiments.

In the above-described second embodiment, the elliptical cam 62 is provided on the upper surface of the rotor 48.
Alternatively, an elliptical cam may be provided in the rotating portion of the speed reducer 42, and a pin 54 may be inserted between the elliptical cam and the motor housing to directly connect the steering handle and the steered wheels.

[0042]

According to the first aspect of the present invention, the input side from the steering wheel of the transmission ratio variable means and the output side for the steered wheels are connected to each other when an excessive reverse input or abnormality occurs in the device. Even when an excessive reverse input is made from the steered wheels, it is possible to prevent the occurrence of a phase shift between the steering wheel and the steered wheels.

According to the second aspect of the present invention, the motor housing and the rotating shaft are connected by the connecting means at the time of excessive reverse input or abnormality of the device, so that excessive reverse input from the steered wheel side. Even if there is, the occurrence of a phase shift between the steering wheel and the steered wheels can be prevented.

According to the third aspect of the present invention, the transmission ratio variable means is a harmonic drive reducer.
By arranging the engaging member in the gap between the circular spline and the flex spline of the speed reducer, the operation of the speed reducer can be stopped, and the steering wheel and the steered wheels can be directly connected. Therefore, there is no need to use special parts such as elliptical cams.

According to the fourth aspect of the present invention, the housing of the motor and the rotating part of the motor are increased and connected by the connecting member extended by the driving means, so that the driving amount by the driving means can be reduced. The driving means can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vehicle steering system according to a first embodiment.

FIG. 2 is a configuration diagram of a variable gear ratio unit of the vehicle steering system according to the first embodiment.

FIG. 3 is a diagram illustrating a pin hole provided in a rotor of the motor of the variable gear ratio unit according to the first embodiment;

FIG. 4 is a configuration diagram of a variable gear ratio unit of a vehicle steering system according to a second embodiment.

FIG. 5 is an AA cross-sectional view of a variable gear ratio unit (FIG. 4) according to a second embodiment.

FIG. 6 is a configuration diagram of a variable gear ratio unit of a vehicle steering system according to a third embodiment.

FIG. 7 is a sectional view of the variable gear ratio unit (FIG. 6) taken along line BB according to the third embodiment;

FIG. 8 is a configuration diagram of a variable gear ratio unit of a vehicle steering system according to a fourth embodiment.

FIG. 9 is a diagram illustrating an operation state of a coupling unit of the variable gear ratio unit according to the fourth embodiment.

[Explanation of symbols]

2 ... Vehicle steering device, 10 ... Steering handle, 1
2a: Upper steering shaft, 12b: Lower steering shaft, 14: Variable gear ratio unit, 16: Steering gear box, 18: Rack bar, 20: Tie rod, 22: Knuckle arm, 24: Steering wheel, 26
... Steering angle sensor, 28 ... ECU, 30 ... Output angle sensor, 3
2: vehicle speed sensor, 40: motor, 42: reducer, 54:
Slide pin, 56 ... solenoid, 66 ... harmonic drive reduction gear, 60, 64, 74 ... variable gear ratio unit.

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Takahiro Ogi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] 1. A vehicle steering system comprising a transmission ratio variable means for varying a transmission ratio by driving a motor in a steering transmission system connecting a steering handle and a steered wheel, wherein the transmission ratio is controlled by an external signal. A steering device for a vehicle, comprising: a connection unit that stops an operation of the variable unit and connects an input side of the transmission ratio variable unit from the steering handle and an output side for the steered wheels. 2. The transmission ratio variable means includes a motor therein, and a steering input of the steering handle is input to a housing of the motor, and a rotation shaft of the motor is output to the reduction gear as an output to the steered wheels. 2. The vehicle steering system according to claim 1, wherein the vehicle is connected, and the connection unit connects the housing and the rotating shaft. 3. The vehicle steering system according to claim 1, wherein said transmission ratio variable means is a harmonic drive reduction gear, and said connecting means projects an engaging member into a gap between a circular spline and a flex spline. 4. The connecting means includes: a driving means provided on a housing of the motor, the driving means being drivable in a direction parallel to an axis of the rotating shaft of the motor; and a connecting member which is expanded and contracted by the driving means. The vehicle steering apparatus according to claim 1, wherein the connecting member is extended by the driving means and connected to a rotating part of the motor.