Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Mitsubishi Denki Kabushiki Kaisha

Yasutaka Taniguchi

Tadao Tanaka

Minoru Tatemoto

Mitsuhiko Harara

Shozo Takizawa

Naotake Kumagai

Masanaga Suzumura

Sunao Chikamori

Hiroki Abe

Takao Morita

Masanori Tani

Shunichi Wada

Shigeki Ohtagaki

Akihiko Togashi

Tsutomu Matsukawa

Hiromichi Yasunaga

Kazuyoshi Kobayashi

Tetsuya Terada

Kouji Mitsuhata

Kenji Hayase

Shinichi Takeuchi

Mitsuhiko Hara

Tadaoa Tanaka

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 pneumatic active suspension apparatus is provided wherein, when a sprung vertical acceleration (ZG), which causes a wafting phenomenon perceptible by a person in a vehicle, occurs during travel of the vehicle, supply/discharge of air to/from air spring chambers of suspension units is carried out for a supply/discharge control time determined based on the maximum value (ZGmax) of the sprung vertical acceleration. The supply/discharge control is started at an advanced time based on the sprung acceleration whose phase is advanced by 90 degrees from that of the sprung velocity, to thereby produce a force acting to cancel out the sprung vertical velocity at proper timing. As a result, the operation delay of the suspension apparatus is compensated for and the sprung vertical motion is suppressed.

Fluid active suspension apparatus and operation control method therefor

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

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.

A suspension control apparatus for an automotive vehicle has a plurality of suspension units which are disposed between each of the wheels of the vehicle and the vehicle body. A plurality of actuators for controlling the characteristics of the suspension units are controlled by a control unit in response to the output of an acceleration sensor. The ground circuit of the acceleration sensor is connected to the ground circuit of the control unit.

Suspension control apparatus for an automotive vehicle

If a deceleration exeeds first set value G1 within set time T1 after the brake is depressed, a set amount of fluid is supplied to the fluid spring chamber of each front-wheel suspension unit. If a deceleration exceeds the second set value G2 when set time T1 or more has elapsed upon this operation, a set amount of fluid is exhausted from the fluid spring chamber of each rearwheel suspension unit. With this operation, since braking action for gradually increasing a deceleration is controlled by two stages, uncomfortableness which passangers feel in anti-nose-dive control can be greatly reduced. In addition, control is not performed only by depressing the brake pedal if an acutal deceleration is smaller than first set value G1. Even when a deceleration exceeds first set value G1 upon depression of the brake pedal, if the time when the deceleration exceeds first set value G1 exceeds set time T1, it is determined that a gradual braking operation is performed, so that only control for increasing a damping force is performed.

Vehicle suspension apparatus

When vibrations having a period at which pitching tends to occur in a vehicle body is detected, if its amplitude falls out of the range between 'H' and 'L', a control unit increases the damping force of each suspension unit by using an actuator. In addition, if the amplitude falls out of the range between 'HH' and 'LL', the control unit supplies a predetermined amount of air to each air spring chamber in response to an upward displacement of vehicle height, and exhausts a predetermined amount of air from each air spring chamber in response to a downward displacement of vehicle height.

A vehicle suspension apparatus comprises a G sensor for detecting lateral acceleration G acting on the vehicle, and a G sensor map for setting the time for supplying/exhausting fluid to and from a fluid spring chamber mounted in each suspension unit in accordance with the lateral acceleration G detected by the G sensor, said lateral acceleration G being higher than a predetermined value. Whether the vehicle is running on a rough road is judged by a rough-road judging routine. When it is judged by the rough-road judging routine that the vehicle is running on a rough road, the non-sensitive area of the G sensor map is widened such that the lateral acceleration G detected by the G sensor is non-sensitive to the G sensor map while the vehicle is running on the rough road, even if the detected lateral acceleration G is somewhat high, thereby preventing the erroneous roll control function.

A vehicle suspension apparatus having a fluid spring chamber provided for each wheel and inserted between the wheel and a vehicle body, a fluid supply unit for supplying a fluid to each fluid spring chamber through a supply valve, a fluid exhaust unit for exhausting the fluid from each fluid spring chamber through an exhaust valve, a roll amount sensor for detecting a roll amount of the vehicle body, and a roll controller for setting a control target corresponding to the roll amount detected by the roll amount sensor and executing roll control in which the supply valves corresponding to the fluid spring chambers at a contracting side with respect to a direction of roll generated in the vehicle body and the exhaust valves corresponding to the fluid spring chambers at an expanding side are opened in accordance with the control target, includes a pressure sensor for detecting an internal pressures in the fluid spring chamber at one of front and rear sides, and an internal pressure relationship memory for storing a mutual relationship between the internal pressure in the fluid spring chambers at the front and rear sides, wherein the control unit calculates control targets at the front and rear sides with reference to said mutual relationship of said internal pressure relationship memory on the basis of the internal pressure detected by the pressure sensor and executes roll control in accordance with the control targets, thereby supplying/exhausting the fluid in/from the fluid spring chambers at the front and rear sides.

A vehicle suspension apparatus having a fluid spring chamber provided for each wheel and inserted between the wheel and a vehicle body, a fluid supply unit for supplying a fluid to each fluid spring chamber through a supply valve, a fluid exhaust unit for exhausting the fluid from each fluid spring chamber through an exhaust valve, a roll amount detector for detecting a roll amount of the vehicle body, and a roll controller for setting a control target corresponding to the roll amount detected by the roll amount detector and executing roll control in which the supply valves corresponding to the fluid spring chambers at a contracting side with respect to a direction of roll generated in the vehicle body and the exhaust valves corresponding to the fluid spring chambers at an expanding side are opened in accordance with the control target, includes a plurality of memories, provided in the roll controller, each for storing a control target corresponding to the roll amount of the vehicle body, the control targets stored in the memories being different from each other, and a selection switch for outputting a selection signal for selecting one of a plurality of memories in the roll controller to the roll controller, wherein the roll controller calculates a control target in accordance with one of the memories selected by the selection switch on the basis of the roll amount detected by the roll amount detector and executes the roll control on the basis of the obtained control target.

A microcomputer performs roll control and communication control. In roll control, when the steering state detecting means and vehicle velocity detecting means detect a factor which causes a roll state of the vehicle body, a second control signal is produced to open desired supply and exhaust control valve so as to supply a preset amount of fluid to the fluid spring chambers of contracted suspension units and to exhaust a preset amount of fluid from the fluid spring chambers of stretched suspension units. In communication control, a first control signal is supplied to the communicating means to open the communication control valve when the steering state sensor detects that the steering angle falls within a preset steering angle and to close the communication control valve otherwise. After generation of the first control signal, when the steering state sensor detects that the steering direction of the steering wheel is in a return direction toward the neutral position and the steering angular velocity is lower than a preset steering angular velocity, a third control signal is supplied to the communicating means so as to open the communication control valve. When the steering state sensor detects, a third preset time after a second preset time from the generation of the third control signal, that the steering angle has reached the preset neutral range, a fourth control signal is produced to close the communication control valve for a fourth preset time.

In a vehicle suspension apparatus having air spring chambers between the vehicle body and the respective wheels to perform height and position control modes by controlling supply control valve means for supplying air to the air spring chambers and exhaust control valve means for exhausting air from the air spring chambers, the vehicle suspension apparatus has a high-pressure reserve tank connected to the respective chambers through the supply control valves, a first compressor for supplying compressed air to the high-pressure reserve tank, a low-pressure reserve tank connected to the respective chambers through the corresponding exhaust control valves and the suction port of the first compressor, and a second compressor for supplying atmospheric air to the high-pressure reserve tank through a check valve and a drier arranged between the check valve and the second compressor. In the position control mode, the compressed air is exhausted from the chambers to the low-pressure reserve tank through the exhaust control valves. In the height control mode, the compressed air is slowly exhausted from the corresponding chambers through the exhaust control valve means via the drier, thereby regenerating the drier during height down control.

In a vehicle suspension apparatus, front and rear wheel suspension units respectively have air spring chambers. Air is supplied to predetermined air spring chambers from an air source through a supply control valve, and at the same time air is exhausted from remaining air spring chambers through an exhaust control valve. Three-directional valves are inserted between the respective air spring chambers and the exhaust control valve. One end of a front wheel communication path is connected to the front left wheel three-directional valve and the other end of the path is connected to the front right wheel three-directional valve. Similarly, one end of a rear wheel communication path is connected to the rear left wheel three-directional valve and the other end of the path is connected to the rear right wheel three-directional valve. The air passing through the supply control valve is supplied to the front wheel air spring chambers through the front wheel communication path or to the rear wheel air spring chambers through the rear wheel communication path. Each of the three-directional valves can take the first position where the air spring chambers communicate with the supply control valve or the second position where the air spring chambers communicate with the exhaust control valve, thereby decreasing the numbers of valves and paths so as to perform position control.

In a vehicle suspension apparatus comprising communication control means for producing a disabling control signal for disabling the communicating solenoid valves when conditions are satisfied that the velocity detected by the velocity sensor exceeds a preset velocity and the steering angle detected by the steering sensor exceeds a preset steering angle and for producing an enabling control signal when the conditions are not satisfied, and roll control means for producing a control command signal for opening desired ones of the supply and exhaust control valves for a preset control time in order to supply a preset amount of fluid to contracted fluid spring chambers along a roll direction and for exhausting a preset amount of fluid from stretched fluid spring chambers when the conditions are satisfied, the preset velocity as one of the conditions determined by the communication control means is set to have a first value when the communicating solenoid valves are enabled and to have a second value larger than the first value when the communicating solenoid valves are disabled. With this apparatus, passengers experience uniform centrifugal force sensations when roll control is started and cancelled. Discomfort experienced by passengers during and after roll control is reduced to a minimum.

A vehicle suspension apparatus including suspension units each provided for each wheel and having an air spring chamber is disclosed, in which rolling control and vehicle height control are done through control of air to and from the air spring chambers. The driving of a reservoir tank for storing compressed air to be supplied to the air spring chambers, is inhibited until the engine operation has been stabilized after the start of the engine preset level. In this way, the problems in the engine lubrication and idling are solved, and the defficiencies of the starting property of the engine are overcome.

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Nagoya, Japan

Yasutaka Taniguchi