Toyota Jidosha Kabushiki Kaisha

Toyoda Koki Kabushiki Kaisha

The Furukawa Electric Co., Ltd.

Jtekt Corporation

Morihiro Matsuda

Junji Kawamuro

Takahiro Kojo

Masahiko Shindo

Shoichi Shono

Motoyasu Yamamori

Osamu Watanabe

Masatoshi Nakatsu

Akihiro Yanaka

Yasunori Okada

Yukihiko Kanayama

Isao Hasegawa

Susumu Sukeda

Tsuguhiro Fujita

Tomio Okamoto

Yasuhisa Toyoshi

A vehicle steering system including: (a) a steering operation member; (b) a movement-amount variably transmitting device including: (b-1) a housing fixed to a vehicle body; (b-2) a differential mechanism including (i) a first element connected to the steering operation member, (ii) a second element movable relative to the first element, and (iii) a third element engaged with the first and second elements; and (b-3) a drive source for moving the third element, such that an amount of relative movement of the first and second elements is changeable depending on an amount of movement of the third element; and (c) a wheel turning device connected to the second element to turn a vehicle wheel. The movement-amount variably transmitting device further includes (b-4) a third-element-movement inhibiting device for inhibiting movement of the third element. The steering system further includes (d) a third-element-movement inhibition cancelling device for cancelling inhibition of the movement of the third element.

Steering system for vehicle

A transfer ratio varying apparatus includes: a steering shaft configured to transmit a steering angle, an actuator connected to the steering shaft and a damper disposed between the input shaft and the steering shaft and configured to absorb vibration caused by the actuator. The actuator includes: a housing, an input shaft configured to integrally rotate with the housing and connected to the steering shaft, a motor including a rotatable shaft, an output shaft configured to transmit an angle to a wheel assembly, and a gear mechanism between the rotatable shaft and the output shaft at the housing, configured to adjust a rotational angle of the rotatable shaft and to output the adjusted rotational angle to the output shaft.

Transfer ratio varying apparatus

A spiral cable device is provided with a cylindrical casing, an inner cylinder rotatable relative to the cylindrical casing, and a flexible flat cable connected to the inner cylinder at one end thereof and to the cylindrical casing at the other end thereof. The flexible flat cable has plural leads arranged in a single layer and is folded to form multiple layers of the leads, so that even where the flexible flat cable is to have many leads, the spiral cable device can be made short in the axial direction thereof.

Spiral cable device

A transmission ratio variable mechanism () varies a transmission ratio between a steering amount of a steering wheel () and a turning amount of wheels (). The transmission ratio variable mechanism () includes an input shaft () transmitted with a rotational force of the steering wheel (), a housing () unitarily rotating with the input shaft (), an output shaft () connected to wheels side, a motor () fixed in the housing for transmitting the rotation to the output shaft () via a speed reduction device (), and a reverse input blocking device () for always transmitting a rotational output from the motor () to the output shaft () and for always blocking a rotational input from the output shaft () to the motor ().

Transmission ratio variable mechanism

A base transmission ratio Gbase is determined according to the vehicle speed and a compensation amount &agr; is determined for each of feed steering case and return steering case during acceleration/deceleration. Based on this, the transmission ratio G of a transmission ratio varying mechanism is set as G&equals;Gbase&plus;&agr;.

Steering control method and apparatus

Target rotational speed of servo motor,is set based on steering speed &thgr;hv detected by steering speed sensor and transmission ratio G set according to a running condition, and speed of servo motor is controlled so that rotational speed &thgr;pv of servo motor detected by rotational speed sensor may agree with the target rotational speed.

Steering control apparatus for vehicle

In a vehicle steering apparatus having a variable gear ratio unit arranged midway along a steering transmission system for connecting a steering wheel and tires to change the transmission ratio, and an ECU for variably controlling the variable gear ratio unit in accordance with the state of a vehicle, the variable gear ratio unit includes a motor controlled by the ECU, and a reducing mechanism which has a transmission ratio for allowing to maintain the steering angle of the steering wheel with respect to an RF reverse input and transmits the rotation of the motor to the output side. Even if a reverse input acts from a tire side during traveling, the relationship between the steering amount of the steering wheel and the turning amount of the tire can be kept unchanged.

Vehicle steering apparatus

A vehicle steering apparatus having a variable gear ratio unit arranged midway along a steering transmission system for connecting a steering wheel and a tire to change a transmission ratio upon driving a motor includes a connecting unit for stopping actuation of the variable gear ratio unit in accordance with an external signal to connect the input side of the variable gear ratio unit which is connected to the steering wheel to the output side of the variable gear ratio unit which is connected to the tire. Even if a reverse input acts from a tire side during traveling, the relationship between the steering amount of the steering wheel and the turning amount of the tire can be kept unchanged.

A torsion bar device includes a torsion bar having a torsional portion, an upper connecting portion associated with an input shaft, and a lower connecting portion associated with an output shaft; a first cylinder for encompassing the torsional portion, one end of the first cylinder being connected to one of the upper and lower connecting portions, and the other end of the first cylinder extending in the longitudinal direction of the torsion bar to the other connecting portion of the torsion bar; a second cylinder for encompassing and being connected to the other one of the upper and lower connecting portions of the torsion bar; a first supporting member for supporting the torsion bar at the other end of the first cylinder in a circumferential direction of the torsion bar; a second supporting member for supporting the torsion bar in the circumferential direction at a portion of the second cylinder where the second supporting member is aligned with the first supporting member; and an elastic member for elastically restoring the alignment of the first and second supporting members by applying a force in a direction opposite to a torsionally stressed circumferential direction of the torsion bar when a steering wheel is turned so as to regain the original neutral position of the steering wheel.

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Toyota, Japan

Morihiro Matsuda