Pump operation control apparatus for hydraulic brake boosting system

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump is allowed to boost the operation of a brake operating member to generate braking force and incorporating a relief valve for relieving hydraulic pressure accumulated in said accumulator when hydraulic pressure has been accumulated in said accumulator to a level not lower than relief pressure, said apparatus comprising:

• relief-valve-operation detecting means for detecting the operation of said relief valve to transmit an output signal;
• and
• pump-operation-signal generating means for transmitting an interruption signal of the pump in response to the output signal from said relief-valve-operation detecting means;
• wherein the operation of the pump is controlled such that the operation of the pump is interrupted when said relief valve has been operated.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump which is operated by a motor is allowed to boost the operation of a brake operating member so as to generate braking force and incorporating a relief valve for relieving hydraulic pressure accumulated in said accumulator when hydraulic pressure has been accumulated in said accumulator to a level not lower than relief pressure, said apparatus comprising:

• motor-current detecting means for detecting an electric current which flows in the motor to produce an output;
• current comparison means for producing an output when the motor current detected by said-motor-current detecting means is higher than a predetermined level;
• and
• pump-operation-signal generating means for transmitting an interruption signal of the pump in response to the output signal from said current comparison means;
• wherein the operation of the pump is controlled such that when the motor current is higher than the predetermined level, the operation of the pump is interrupted.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump which is operated by a motor is used to boost the operation of a brake operating member so as to generate braking force, said apparatus comprising:

• motor-revolution-number detecting means for detecting the number of revolutions of the motor to produce an output;
• revolution-number comparison means for producing an output when the number of revolutions detected by said motor-revolution-number detecting means is smaller than a predetermined value;
• and
• pump-operation-signal generating means for transmitting an interruption signal of the pump in response to the output signal from said revolution-number comparison means;
• wherein the operation of the pump is controlled such that when the number of revolutions of the motor is smaller than the predetermined value, the operation of the pump is interrupted.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump is allowed to boost the operation of a brake operating member so as to generate braking force, said apparatus comprising:

• pulsating-frequency calculating means for calculating a pulsating frequency of pulses generated when the pump is operated;
• pulsating-frequency comparison means for producing an output when the pulsating frequency calculated by said pulsating-frequency calculating means is lower than a predetermined value;
• and
• pump-operation-signal generating means for transmitting an interruption signal of the pump in response to the output signal from said pulsating-frequency comparison means;
• wherein the operation of the pump is controlled such that when the pulsating frequency is lower than the predetermined value, the operation of the pump is interrupted.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump is allowed to boost the operation of a brake operating member to generate braking force and the operation of the pump is controlled in response to a pump-operation control signal transmitted from a pump-operation-signal generating means in response to an output signal from a pump-operating-pressure sensor for detecting accumulation of hydraulic pressure in the accumulator, said apparatus comprising:

• pressure-sensor-failure detecting means for detecting a failure of the pump-operating-pressure sensor;
• a backup sensor for detecting accumulation of hydraulic pressure in the accumulator and arranged to be turned off at OFF pressure which is lower than OFF pressure for said pump-operating pressure sensor;
• a timer for measuring time required from a moment at which the OFF pressure of said backup sensor is realized to a moment at which the OFF pressure of said pump-operating pressure sensor is realized when said pump-operating pressure sensor is operated normally;
• and
• storage means for learning and storing the time measured by said timer;
• wherein said pump-operation-signal generating means transmits an operation-control signal for the pump in response to the output signal from said pump-operating pressure sensor when said pump-operating pressure sensor is in a normal state, and when a failure of said pump-operating pressure sensor has occurred, said pump-operation-signal generating means transmits an operation signal of the pump in response to an ON signal of said backup sensor and transmits an interruption signal of the pump for time elongated from an OFF signal of said backup sensor and corresponding to time learned and stored in said storage means.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump which is operated by a motor is used to boost the operation of a brake operating member to generate braking force and that the operation of the pump is controlled in response to a pump-operation-control signal transmitted from a pump-operation-signal generating means in response to an output signal from a pump-operating pressure sensor for detecting accumulation of hydraulic pressure in the accumulator and incorporating a relief valve for relieving hydraulic pressure accumulated in said accumulator when hydraulic pressure has been accumulated in said accumulator to a level not lower than relief pressure, said apparatus comprising:

• pressure-sensor-failure detecting means for detecting a failure of the pump-operating-pressure sensor;
• a backup sensor for detecting accumulation of hydraulic pressure in the accumulator to produce an output;
• and
• relief-valve detecting means for detecting the operation of the relief valve and producing an output;
• wherein when said pump-operating pressure sensor is in a normal state, said pump-operation-signal generating means transmits an operation control signal for the pump in response to an output signal from said pump-operating pressure sensor, and when a failure of said pump-operating pressure sensor has occurred, said pump-operation-signal generating means transmits an operation signal of the pump in response to an ON signal of said backup sensor and transmits an interruption signal of the pump to interrupt the operation of the pump when said relief valve has been operated.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump which is operated by a motor is allowed to boost the operation of a brake operating member to generate braking force and that the operation of the pump is controlled in response to a pump-operation-control signal transmitted from a pump-operation-signal generating means in response to an output signal from a pump-operating pressure sensor for detecting accumulation of hydraulic pressure in the accumulator, said apparatus comprising:

• pressure-sensor-failure detecting means for detecting a failure of the pump-operating-pressure sensor;
• a backup sensor for detecting accumulation of hydraulic pressure in the accumulator and producing an output;
• motor-current detecting means for detecting an electric current which flows in the motor to produce an output and current comparison means for producing an output when the motor current detected by said motor-current detecting means is higher than a predetermined level;
• wherein said pump-operation-signal generating means transmits an operation control signal for the pump in response to an output signal from said pump-operating pressure sensor when said pump-operating pressure sensor is in a normal state, and when a failure of said pump-operating pressure sensor has occurred, said pump-operation-signal generating means transmits an operation signal of the pump in response to an ON signal of said backup sensor and transmits an interruption signal of the pump to interrupt the operation of the pump when the motor current has been raised to a level not lower than the predetermined value.

A pump operation control apparatus for a hydraulic brake boosting system wherein hydraulic pressure in an accumulator accumulated by a pump which is operated by a motor is allowed to boost the operation of a brake operating member to generate braking force and that the operation of the pump is controlled in response to a pump-operation-control signal transmitted from a pump-operation-signal generating means in response to an output signal from a pump-operating pressure sensor for detecting accumulation of hydraulic pressure in the accumulator, said apparatus comprising:

• pressure-sensor-failure detecting means for detecting a failure of the pump-operating-pressure sensor;
• a backup sensor for detecting accumulation of hydraulic pressure in the accumulator and producing an output;
• motor-revolution-number detecting means for detecting the number of revolutions of the motor to produce an output;
• and
• revolution-number comparison means for producing an output when the number of revolutions detected by said motor-revolution-number detecting means is smaller than a predetermined value;
• wherein said pump-operation-signal generating means transmits an operation control signal for the pump in response to an output signal from said pump-operating pressure sensor when said pump-operating pressure sensor is in a normal state, and when a failure of said pump-operating pressure sensor has occurred, said pump-operation-signal generating means transmits an operation signal of the pump in response to an ON signal of said backup sensor and transmits an interruption signal of the pump to interrupt the operation of the pump when the number of revolutions of the motor is smaller than the predetermined value.