Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Other

Shinichi Inagawa

Shohei Matsuda

Toshio Yahagi

Akihiro Iwazaki

Tatsuhiro Tomari

Shinji Ohkuma

Yukihisa Ishii

Koji Matsubara

Yasuji Shibahata

Yoshihiro Urai

Masaaki Kusumi

Hiroshi Ikegami

Yasuo Nekado

Yutaka Tashiro

Yutaka Kichima

Ken Onoe

Masayoshi Wada

Yetsuya Oono

A differential with a differential action limiting mechanism includes a differential mechanism D for distributing the drive force of an internal combustion engine inputted into a differential caseto a left-hand axle shaftand a half shaftwhich continuously connects to a right-hand axle shaft for output therefrom and friction clutchesL,R for limiting differential rotations of the left-hand axle shaftand the half shaftrelative to the differential case. An actuator A for generating an engagement force for bringing the friction clutchesL,R into engagement is provided outside a housingfor accommodating therein the differential case, whereby an engagement force generated by the actuator A is transmitted to the friction clutchesL,R via the half shaft

Limited slip differential

Two sensors are provided on a clutch core. Sensor coils are driven at a high frequency by a high-frequency driving circuit. As the sensors sense a magnetic flux of a magnetic circuit including the clutch core and an armature, the impedance of the sensor coils changes. In accordance with the outputs from the sensor coils at this point, an impedance detecting circuit detects the impedance of the sensor coils. Then, an impedance combining circuit combines the impedance of the sensor coils. On the basis of the combined impedance, a current control circuit controls a current supplied to an exciting coil. Thus, the attracting force of the armature to the core excited by the exciting coil is controlled.

Electromagnetic clutch

A driving-force controller in a vehicle in which, when an accelerator pedal is depressed to initially move the vehicle at a time t.sub.1, if a state in which a vehicle speed is zero due to slippage of driven wheels continues for a predetermined time, it is judged that the vehicle is on a road surface having an extremely low road surface friction coefficient. If a driven wheel speed and the vehicle speed become zero at a time t.sub.4 because a driver abandons initial acceleration and releases an accelerator pedal, a gear shift stage of an automatic transmission is forcibly shifted to a second gear shift stage, and a target slip rate set in a traction control device is switched to a decreased value. As a result, when the driver depresses the accelerator pedal to restart the vehicle at a time t.sub.5, excessive slippage is suppressed by a decrease in driven wheel torque so that the vehicle begins moving smoothly. If a driven wheel slip rate exceeds the decreased target slip rate at a time t.sub.6, engine power output is immediately decreased by the traction control to further effectively suppress excessive slippage.

Driving force controller in vehicle for forcibly upshifting in response

A fluid pressure boosting type brake system includes a fluid pressure source including a fluid pump and a pressure tank connected to the pump, and a control valve capable of controlling the output pressure from the fluid pressure source to a fluid pressure corresponding to the degree of brake operation to output it. In this brake system, the fluid pump can be driven in accordance with the consumption of fluid pressure in a brake device, thereby insuring a reliable sufficient fluid pressure in the fluid pressure source.

Fluid pressure boosting type brake system

A method for detecting trouble in a fluid pressure system which has a fluid pressure source including a fluid pump, a pressure tank connected to the pump, a pressure detector for detecting fluid pressure in the pressure tank, and a control device for controlling the operation of the fluid pump on the basis of an output signal from the pressure detector, comprising the steps of operating such fluid pressure systems with output fluid pressure from the fluid pressure source, detecting variation in the output signal from the pressure detector and when the output signal is less than a first predetermined value during operation of the fluid pressure system driving said fluid pump regardless of the output signal from the pressure detector, and when the variation in output signal from the pressure detector is less than a second predetermined value as a result of such driving of said fluid pump energizing a signal to indicate that the system is out of order. During operation of said system, monitoring the fluid pressure detected by said pressure detector for reliably and accurately detecting trouble in the system.

Method for detecting trouble in fluid pressure system and fluid pressure

A traction control method for a vehicle, comprising the steps of: judging an excessive slipping state of a plurality of driving wheels by taking into account, as at least one judgment requirement, whether or not a driving-wheel speed exceeds a braking-force controlling target wheel speed determined by taking into account a predetermined slip rate of a vehicle speed, and controlling a braking force for the driving wheels in accordance with the result of the judgment, wherein the intensity of a slipping tendency for every one of the driving wheels is determined on the basis of a judgment value which is set larger than the vehicle speed and smaller than the braking-force controlling target wheel speed, and the smaller the number of the driving wheels determined to have a large slipping tendency, the more the braking-force controlling target wheel speed is increased. This prevents the occurrence of an excessive control of braking force, when the slipping tendency of only a part of the driving wheels is large.

Traction control method for vehicle

A data communication system transmits a first data signal from a first control unit to a second control unit. The data communication system includes a clock signal line for transmitting a clock signal between the first and second control units. In performing data communication, the first control unit first transmits a first trigger signal via a first trigger signal line to the second control unit for informing the second control unit of the start of transmission of the first data signal. The first control unit then transmits the first data signal via a first data signal line to the second control unit. A second trigger signal line transmits a second trigger signal from the second control unit to the first control unit for informing the first control unit of the start of transmission of the second data signal. The second control unit then transmits the second data signal via a second data signal line to the first control unit in synchronization with the clock signal.

Data communication system

A pressure source for a pressure device includes a pump for pumping fluid from fluid tank, an accumulator connected to the pump and a pressure device, a device for detecting the pressure in the accumulator, and a controller for controlling the operation of the pump in an ON-OFF manner on the basis of a result of detection by the pressure detecting device. In this pressure source, the controller includes first and second drive signal generating circuits each capable of independently generating a drive signal for determining the on-off operation of the pump, and a judging circuit which has a calculating function therein and to which at least the pressure detecting device is connected. The judging circuit is connected to the first drive signal generating circuit, and the pressure detecting device is connected to the second drive signal generating circuit. This ensures that the control of the first drive signal generating circuit can be carried out at any time by a calculation in the judging circuit, leading to an increased function. When the judging circuit is in trouble, the on-off control of the pump can be carried out by the second drive signal generating circuit.

Pressure source for pressure device

A pressure source for a pressure device has a pump for pumping fluid from a tank, an accumulator connected to the pump and to a pressure device, a device for detecting the pressure in the accumulator, and a control system for controlling the operation of the pump in an ON/OFF manner based on results of detection of the pressure detecting device. The pressure detecting device includes a pressure switch to detect pressure in the accumulator to produce an ON/OFF signal, and a pressure sensor outputting a pressure signal corresponding to pressure in the accumulator. The control system judges whether the pressure sensor is normal or out of order, and when the pressure is normal, controls the operation of the pump with the pressure signal. The pressure signal and the ON/OFF signal are compared with each other, and when these signals do not correspond, the pressure switch is determined to be out of order, and when the pressure sensor is out of order, the pump operation is controlled with the ON/OFF signal. In this way, the pump can be controlled appropriately, irrespective of any trouble or abnormality in the detecting device.

A driving circuit for driving a stepping motor has a plurality of excitation coils, a plurality of excitation transistors for driving the excitation coils of the stepping motor, respectively, and at least one chopping transistor for effecting chopping control of current flowing to the excitation coils. A fault diagnosis transistor is connected in parallel with the chopping transistor. A current limiting resistance is serially connected to the fault diagnosis transistor. A CPU selectively turns on and off the fault diagnosis transistor. The CPU detects output states of the chopping transistor assumed respectively when the fault diagnosis transistor is turned on and turned off. The CPU compares the detected output levels of the chopping transistor with respective predetermined logic levels and detects faults in the driving circuit from results of the comparisons.

Stepping motor driving circuit having failsafe function

A driving circuit for driving a stepping motor has a plurality of excitation coils, a plurality of excitation transistors for driving the excitation coils of the stepping motor, respectively, at least one chopping transistor for effecting chopping control of current flowing to the excitation coils, and a CPU for supplying at least one control signal to the at least one chopping transistor. High and low pulse duty factor detecting circuits detect whether the at least one control signal has a pulse duty factor thereof falling outside a predetermined range defined by predetermined upper and lower limit values. The CPU is responsive to outputs from the high and low pulse duty factor detecting circuits for interrupting the supply of current to the stepping motor when the latter detect that the pulse duty factor falls outside the predetermined range.

Growing community of inventors

Wako, Japan

Shinichi Inagawa