Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Akihiko Togashi

Tadao Tanaka

Takao Morita

Hiroaki Yoshida

Yasutaka Taniguchi

Masanori Tani

Tsutomu Matsukawa

Naohiro Kishimoto

Hiromichi Yasunaga

A control method and an apparatus therefor, in which the braking force distribution to rear wheels is increased in a normal state, while the braking force distribution to the rear wheels is reduced to prevent the rear wheels from being locked in an early stage when the road surface is slippery. There are provided a pressure sensor (74) for detecting a master cylinder pressure, proportioning valves (57.sub.1, 57.sub.2) arranged in passages which connect a master cylinder and rear wheel cylinders and adapted to operate so that the ratios of the wheel cylinder pressures to the master cylinder pressure are low in a region where the master cylinder pressure is not lower than a predetermined pressure, normally-open switching valves (62, 63) by-passing the two valves, and a controller (71). The controller closes the switching valves to actuates the proportioning valves when the master cylinder pressure detected by the pressure sensor is not lower than a set pressure which lowers depending on the slipperiness of the road surface.

Rear wheel braking force control method and an apparatus therefor

A system is for controlling a suspension performance detecting the road surface condition in front of an automotive vehicle. A road surface sensor generates an output corresponding to the size of roughness on a road surface located at a predetermined distance in front of the vehicle. A suspension damping coefficient is changed to a smaller value upon lapse of a delay time. The delay time is calculated on the basis of the output of a speed sensor, the delay time being the time required for the wheel to reach the detected rough roads surface. The changing of the suspension damping coefficient occurs on condition that the output of the road surface sensor falls within a control region defined by a lower threshold value and an upper threshold value. Accordingly, the change of the suspension damping coefficient to a smaller value is inhibited when an extremely rough road surface is detected in front of the vehicle, whereby a bottoming out of the suspension which may occur is prevented when the vehicle runs over the extremely rough road surface. Further, the ride feeling is improved when the vehicle runs over a moderately rough road surface.

Suspension control system for automotive vehicle

A vehicular suspension control apparatus includes a selector valve for changing at least one of spring rigidity or damper rigidity of a suspension which is installed between a wheel and a body of a vehicle and extensibly and retractably supports the vehicle body on the wheel, a forward road surface sensor attached to the vehicle body and adapted to detect an irregularity of a road surface located in front of the vehicle body at a predetermined distance from the mounting position of the sensor when the vehicle body is in a predetermined attitude, a vehicle speed sensor for detecting a vehicle speed, and a controller for calculating a point of time when the wheel reaches the irregularity of the road surface, in accordance with the vehicle speed detected by the vehicle speed sensor, when the irregularity of the road surface is detected by the forward road surface sensor, and delivering a command signal for lowering at least one of the spring rigidity and the damper rigidity of the suspension to the selector valve by not later than the calculated time point.

Method and apparatus for controlling vehicle suspension such that

A rear wheel braking force control apparatus of a vehicle includes a pressure sensor 74 for detecting master cylinder pressure, right and left proportioning valves 57.sub.1 and 57.sub.2 individually disposed in passages for transmitting master cylinder pressure to right and left wheel cylinders of the rear wheels for controlling to decrease changes in wheel cylinder pressure relative to changes in master cylinder pressure, right and left PCV bypass valves 62 and 63 for individually bypassing the proportioning valves, and a controller 71 which, when the vehicle is determined by a steering angle sensor 77 or the like to be turning, closes the PCV bypass valve at the outer wheel side when the master cylinder pressure is higher than the pressure of the PCV bypass valve at the inner wheel side.

Apparatus and method for controlling rear wheel braking force of vehicle

An active suspension apparatus is provided for a vehicle which includes an actuator being extensible and retractable and provided between a vehicle body and a wheel so that the force of the vehicle body to support the wheel is adjustable, a sprung G sensor or a vehicle height sensor for detecting a vibration input to the vehicle body, and a control valve and a controller for controlling the supporting force of the actuator in accordance with the vibration input detected by the sprung G sensor or the vehicle height sensor, and thereby restraining the stroke of the actuator. The suspension apparatus further comprises a forward road surface sensor for detecting the size of irregularities of a road surface in front of the vehicle, and the control valve and the controller are adapted to execute normal control such that the equivalent spring constant of the actuator is adjusted to a first spring constant when a surface irregularity of a size larger than a predetermined size is detected by the forward road surface sensor, and to execute inverse spring control such that the equivalent spring constant of the actuator is adjusted to a second spring constant lower than the first spring constant, and thereby lengthening the stroke of the wheel, when no surface irregularity of a size larger than the predetermined size is detected by the forward road surface sensor. As a result, the ride is greatly improved when the vehicle runs on a smooth road.

Active suspension apparatus for a vehicle

When a master cylinder pressure detected by way of a pressure sensor (74) attains a level not lower than a target pressure (P.sub.OK), normally-open on-off valves (62, 63) for by-passing proportioning control valves (57.sub.1, 57.sub.2) are opened. If the slip factor of rear wheels, calculated by way of a slip factor calculation section (121), is not lower than a predetermined value, the on-off valves (64, 66) are opened to allow the rear wheel cylinder pressure to escape to accumulators (65, 67). Thus, if there is enough room for the increase of the braking force on the rear wheels, the rear wheel braking force can be increased to reduce the share of the front wheel braking force, depending on braking conditions, such as the road surface conditions, vehicle running conditions, etc. Further the rear wheels can be prevented from being locked.

Growing community of inventors

Okazaki, Japan

Akihiko Togashi