Toyoda Koki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Kunihiko Eto

Yutaka Mori

Kazumasa Kodama

Akihiro Ohno

Shigeo Tanooka

Kaoru Owa

Shiro Takeuchi

Keiichi Nakamura

Hideo Nishimura

Tsutomu Matsumoto

Kuniyuki Niwa

Shigeo Iwashita

Akihiro Oono

Keiji Suzuki

Mikio Suzuki

Kenji Nomura

Kyosuke Haga

Kunimichi Nakashima

Tetsuro Yamakage

Akira Tsuboi

Tamaki Tomita

Shigeo Noda

Kiyotaka Kato

Susumu Oda

Hisaji Nakao

Sadamu Kato

Haruo Ohmura

Yoshio Shima

Junichi Miyagi

Masaaki Hayashi

Tadashi Koyama

Hidemi Masuda

Fumio Ukai

Tetsurou Yamakage

Shiro Seki

Akira Ohnishi

Syuichi Nakada

Hideo Mizoguchi

Kozo Ohno

Hisashi Koba

Yuzo Kubota

Kimio Yamaguchi

Shirou Takeuchi

Yasuo Shiba

A control apparatus for a power-assisted steering system which includes a servo valve associated with a hydraulic power cylinder to selectively direct the flow of fluid under pressure from a source of hydraulic pressure to opposite fluid chambers of the power cylinder in response to operation of a steering wheel and an electrically operated control valve arranged to control hydraulic pressure for power assist applied to the servo valve in accordance with a control current applied thereto. The control apparatus is arranged to control the value of the control current in such a manner that the hydraulic pressure for power assist is decreased when the steering wheel is returned to its neutral position from its steered position during low speed travel of the vehicle and that the hydraulic pressure for power assist is increased when the steering wheel is returned to its neutral position from its steered position during high speed travel of the vehicle.

Control apparatus for power-assisted steering system

An apparatus for controlling the ratio of a assisting force produced by a power steering system installed in an vehicle to a steering torque supplied by the driver wherein the ratio is changed by a solenoid valve arranged in the power steering system. The CPU of the apparatus changes control current to be applied to the solenoid valve using a characteristic map defining change of a base current with respect to changes of the vehicle speed and the steering angle. Further, the CPU increases the control current, when the steering wheel is returned to its neutral angle position, so as to decrease the ratio, increasing the self returning ability of the steering mechanism. The control current applied to the solenoid valve during the returning operation is changed depending upon both the steering angle and the steering speed of the steering wheel using additional characteristic maps.

Apparatus for controlling steering force produced by power steering

A four-wheel steering system for an automotive vehicle in which a cable linkage is adapted to operatively interconnect front and rear wheel steering mechanisms. The cable linkage is provided with a displacement transmitting mechanism which includes an input element operatively connected to a front lateral bar in the front wheel steering mechanism through the cable linkage, an output element operatively connected to the rear wheel steering mechanism, and a spring element disposed between the input and output elements to transmit displacement of the input element to the output element without any deflection in a condition where the output element is freely movable and to absorb displacement of the input element in a condition where the output element is restrained by an excessive load applied thereto from the rear wheel steering mechanism.

Four-wheel steering system for automotive vehicles

A torque sensor for use with an automotive steering system. The sensor includes a driving shaft, a driven shaft, a sleeve cylinder fitted over one of the shafts so as to be rotatable and axially movable, a differential transformer, first and second connector members, a spring, and a torsion bar. The amount of axial movement of the sleeve cylinder is detected by the transformer. The connector members are inclined in opposite directions within a plane parallel to the axis of the shafts. One end of the first connector member is connected to the cylinder, while the other is connected to the driving shaft. One end of the second connector member is connected also to the cylinder, the other being connected to the driven shaft. Torque is transmitted from the driving shaft to the driven shaft via the torsion bar. The spring is mounted between one of the shafts and the sleeve cylinder.

Torque sensor

A device for detecting driving condition faced by an operator of an automobile. The device includes an automobile speed sensor, first arithmetic means, second arithmetic means and compensating means. The first arithmetic means computes a driving condition index by using automobile speed information. The second arithmetic means computes limit value changing according to the increment in the automobile speed. The compensating means compare the change amount of the driving condition index for a predetermined time period with the limit value and compensate the driving condition index in such a way that the change amount of the driving condition is limited to the limit value when the change amount exceeds the limit value in order to give the operator a natural feel of the road.

Device for detecting driving condition for automobile

A torque sensor in which a main shaft and a follower shaft are supported rotatably relative to each other on a common axis. A sleeve is supported axially slidable on one of the main and follower shafts. A deviation sensor is responsive to axial movement of the sleeve to output a signal corresponding to the quantity of the axial movement. At least one set of torque transmitting members is provided to transmit the torque applied to the main shaft to the follower shaft and to move the sleeve axially in accordance with the torque. The at least one set of torque transmitting members comprises a first connection body extending parallel to the common axis, inclined in a plane offset radially of the main and follower shafts, and connected at one and the other ends to the sleeve and main shaft, respectively. It also includes a second connection body provided inclined in the plane and in the opposite direction to that in which the first connection body is inclined, and connected at one and the other ends to the sleeve and the follower shaft, respectively.

There is disclosed a device for controlling steering force in a power steering apparatus having an electromagnetic control valve according to road and driving conditions. The device includes a car speed sensor, a steering angle sensor, first arithmetic means, second arithmetic means, correcting means, control current arithmetic means and controlling means. The first arithmetic means computes a driving condition index by using car speed information. The second arithmetic means computes a road condition index by using steering angle signals. The correcting means converts the driving condition index into a correction driving condition index which takes any one of several stepwise-varied values. The control current arithmetic means computes an output control current value applied to electromagnetic control valve by the controlling means. The device further includes means for detecting lateral acceleration utilized for controlling the steering force.

Device for controlling steering force in power steering apparatus

There is disclosed an apparatus for controlling the ratio of the assisting force produced by a power-steering system installed in an automobile to the steering torque supplied by the driver. The apparatus primarily consists of a microprocessor, a ROM, and a RAM. The microprocessor controls the amount of current supplied to a solenoid valve according to the velocity of the automobile. The aforementioned ratio is varied according to the driver's condition and the road condition. Four graphs representing the relation of the electric current supplied to the solenoid valve to the angle through which the steering wheel is rotated are stored in the ROM. Each graph has two characteristic curves for two different values of the velosity of the automobile. The microprocessor calculates a driver's condition index from the output signal from a velocity sensor. Also, it calculates a road condition index from the output signal from a steering angle sensor. The value of the current supplied to the solenoid valve is selected from the data stored in the ROM according to these indices.

Apparatus for controlling steering force produced by power-steering

Steering angle detection device

A steering force controller for an automobile power steering device includes a solenoid-operated valve openable and closable by a current applied to a solenoid thereof for controlling a fluid supplied under pressure to a power cylinder for operating steerable wheels, an automobile speed sensor for detecting a speed of travel of the automobile, a steering angle sensor for detecting a steering angle of the steering wheel and issuing a signal indicative of the detected steering angle, a discriminator for determining a running mode of the automobile from a variance of steering angle signals, and a control unit responsive to an output from the discriminator for controlling the current fed to the solenoid dependent on an input signal indicating the automobile speed, according to a respective one of different control patterns.

Steering force controller for power steering device

An assisting power controller for a vehicle power steering device is provided with a microcomputer, which stores in a random access memory a plurality of the latest steering angle data each detected from a steering angle detector each time the vehicle runs a predetermined distance. The microprocessor processes the plurality of steering angle data to calculate a first driving index representing the road condition and then, to decide a first electric current meeting the road condition. The microprocessor also stores in the memory a plurality of the latest vehicle speed data each detected from a speed sensor each time the vehicle runs the predetermined distance. The microprocessor processes the plurality of vehicle speed data to calculate a second driving index representing the state of maneuver by the driver of the vehicle and then, to decide a second electric current meeting the state of maneuvering. The microprocessor thereafter makes an addition of the first and second electric currents and applies the added electric current to an electromagnetic flow control valve which controls the bypass communication of pressurized fluid between opposite chambers of a power cylinder, to control the assisting power generated by the power cylinder based on the road condition and the state of maneuvering by the driver of the vehicle.

Assisting power controller for an automotive power steering device

A motor vehicle is provided with a driving status discrimination device, which includes a detector for detecting a parameter signal (e.g., vehicle speed, engine rotational speed, the opening degree of an engine throttle valve, or the like) relating to the driving speed of the motor vehicle at a predetermined interval, and a microcomputer for processing the parameter signals input thereto. The microprocessor calculates a differentiated value of the parameter signal and stores the differential value in a memory device. The memory device has a plurality of memory locations each storing the differential value. The microprocessor futher calculates an integrated value of a plurality of differentiated values stored in the memory device and discriminates various driving status from one another (e.g., a mountain road driving from a high speed driving) based upon the calculated integrated value.

Motor vehicle with driving status detection device

A motor vehicle is provided with a driving status discrimination device, which includes a steering angle sensor for detecting the rotational angle of a steering wheel and a microcomputer for reading and processing the steering angle signal each time the vehicle runs a predetermined distance. The microcomputer identifies one of steering angular ranges of intervals to which each detected steering angle belongs so as to record the frequency at which the steering wheel was turned to each steering angular interval. The microcomputer modifies the frequency for each steering angle interval with a weighting coefficient determined for the steering angular interval and then, calculates a total or integrated value of the modified frequencies for the steering angular intervals. Further, the microcomputer discriminates town street driving from mountain road driving based upon the integrated value so that the assisting power generated by a power steering mechanism of the motor vehicle can be controlled based upon the result of such discrimination.

Motor vehicle with driving status discrimination device

A driving status discrimination device for a motor vehicle is provided with a microcomputer, which stores in a memory a plurality of the latest steering angle signals which are output from a steering angle detector each time the vehicle runs a predetermined distance. The microcomputer processes the steering angle signals stored in the memory to calculate a discrimination value and then, compares the discrimination value with a predetermined reference value, so that the driving state of the vehicle can be judged to be either of a mountain road driving and a town street driving. To calculate the discrimination value, the microcomputer in one embodiment searches said memory for some of the steering angle signals whose values belong to a particular one of classification intervals and calculates the ratio of said searched steering angle signals to all of the steering angle signals stored in the memory. Also to calculate the discrimination value, the microcomputer in another embodiment calculates a mean value of absolute values of the steering angle signals stored in the memory.

Driving status discrimination device for a motor vehicle

Steering force controller for a power steering apparatus

Growing community of inventors

Toyota, Japan

Kunihiko Eto