JPH0733002A - Warning device for liquid-operated brake booster - Google Patents

Abstract

PURPOSE:To improve reliability of warning and safety by delaying warning in the case of generating warning when liquid pressure accumulated in an accumulator reduced is to its lower limit or less, and stopping warning delay when the pressure rise gradient of the accumulator is less than a prescribed one. CONSTITUTION:Pressure is accumulated in an accumulator by a pump which is driven by a motor, and brake stepping-power is boosted by a liquid pressure booster, so that a master cylinder is operated. The motor is operated or stopped by a motor operating circuit C11 connected to a battery 111 through an ignition switch 132 according to the liquid pressure in the accumulator. When liquid pressure drops to the lower limit or less, warning is generated in a warning circuit C12. In the above constitution, the action of the warning circuit C12 delayed by prescribed time by means of a warning delay circuit C14. The pressure rise gradient of the accumulator is detected by its detection circuit C15, and when the detected value is less than a prescribed one, the action of the warning delay circuit C14 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake booster, and more particularly to a warning device for a hydraulic brake booster which detects an abnormality in the hydraulic brake booster and issues a warning.

[0002]

2. Description of the Related Art In a conventional hydraulic brake booster, the pedaling force applied to a brake pedal is increased via a hydraulic booster and transmitted to a master cylinder so that the hydraulic pressure generated in the master cylinder is applied to the front wheel and It is sent to the wheel cylinder of the rear wheel to perform the braking action.

The accumulator is accumulated by a pump driven by a motor, and the hydraulic booster is operated by the hydraulic pressure of the accumulator. A check valve is provided between the accumulator and the pump. As shown in FIG. 11, a hydraulic pressure sensing type motor activating pressure switch 22 and a warning pressure switch 24 are connected between the check valve and the pump.

The pressure switch 22 for operating the motor is
As shown in FIG. 11, a motor operating circuit C1 is configured with the motor relay 23. The motor operating pressure switch 22 is turned on when the hydraulic pressure of the accumulator is released and the hydraulic pressure drops to a predetermined value, and the motor operating circuit C1 is activated.
Is operated to operate the motor 12 to drive the pump 14. Then, when the hydraulic pressure rises to a predetermined pressure and the pressure accumulation is completed, it is turned off and the motor 12 is stopped.

The warning pressure switch 24 is
As shown in FIG. 11, a warning relay 25 and a warning buzzer 30
A warning circuit C2 is constituted by the warning lamp 31 and is turned on when the hydraulic pressure of the accumulator drops to a set hydraulic pressure lower than the hydraulic pressure for operating the pump 12 due to a failure of the motor operating pressure switch 22 or the like. The warning buzzer 30 and the warning lamp 31 are activated to give a warning.

In the above-mentioned warning device of the conventional hydraulic brake booster, the hydraulic pressure of the accumulator is detected by the hydraulic pressure sensing type warning pressure switch 24, and when the hydraulic pressure of the accumulator falls below a set value, a warning is given. The driver is warned by the circuit C2. by the way,
Even if the hydraulic brake booster is not a malfunction of the system, when the vehicle is parked for a long time, a small liquid leak occurs inside the system from the valve etc. inside the hydraulic brake booster, and the hydraulic pressure accumulated in the accumulator is accumulated. Pressure may escape to the hydraulic booster oil tank. Since the warning circuit C2 is designed to issue a warning by sensing the hydraulic pressure, the warning may be issued for a certain period of time from the start of the engine until the normal boosting function is restored. It may be difficult to distinguish whether the system is abnormal or not, and the driver may feel uneasy.

Therefore, as shown in FIG. 12, a warning delay circuit C3 is provided in the warning circuit C2, and the operation of the warning circuit C2 is stopped for a certain period of time after the engine is started (the ignition switch 132 is turned on). A device has been proposed. For example, when the vehicle is parked for a long time, a small fluid leak occurs from a valve or the like inside the hydraulic brake booster, and the hydraulic pressure of the accumulator drops to 0, the certain period of time is It is the time from the start of the process until the accumulator completes pressure accumulation and returns to the normal boosting function. The warning delay circuit C3 is electrically connected to the warning delay timer 32 electrically connected to the battery 111 via the ignition switch 132, and electrically connected to the warning delay timer 32, and operates as a relay contact according to the operation of the warning delay timer 32. A delay timer relay 33 for switching ON / OFF is provided. In the warning delay circuit C3, after the ignition switch is turned on, the warning delay timer 32 operates for a predetermined time to excite the coil of the delay timer relay 33 to open the relay contact.
Turn off. Therefore, even if the hydraulic pressure of the accumulator is less than or equal to the set value, the warning circuit C2 is
No warning is given.

[0008]

In the conventional warning device for a hydraulic brake booster having the above-described structure, when the system itself has no abnormality and pressure is normally stored in the accumulator, it is caused by a long stoppage of the vehicle. There is no problem in deactivating the warning circuit C2 for a predetermined time after starting the engine in consideration of a minute liquid leak in the system. However, if a failure occurs in the pump, the motor, and the motor operating circuit as the pressure accumulator, the pressure is not normally stored in the accumulator, and even if the brake boosting function is impaired, the predetermined time after the engine starts. During this period, the warning circuit C2 does not operate, and the vehicle runs without issuing a warning to the driver, which is a safety problem.

The present invention has been made in order to eliminate the above-mentioned drawbacks. Even if the warning circuit is inactive for a certain time after the engine is started, it is possible to detect the system abnormality by detecting the pressure accumulation state in the accumulator. In the event of an abnormality, a warning device for a hydraulic brake booster that can release the warning circuit inactive state and immediately give a warning to the driver to increase the reliability of the warning and improve safety. It is provided.

[0010]

A warning device for a hydraulic brake booster according to the present invention includes a pump driven by a motor, an accumulator accumulated by the pump, and a hydraulic pressure of the accumulator for brake operation. When the hydraulic booster that boosts the brake pedal force to operate the master cylinder is electrically connected to the battery via the ignition switch, it turns on when the hydraulic pressure of the accumulator drops to a specified value When the motor is activated and the pressure is accumulated to a specified value, the motor is turned off to stop the motor, and when the hydraulic pressure of the accumulator drops to a specified pressure below the pressure to operate the motor, a warning is issued by a warning device. In a hydraulic brake booster equipped with a warning circuit, activate the warning circuit after turning on the ignition switch. And warning delay circuit to time delay,
It is electrically connected to this warning delay circuit and detects the pressure change per unit time of the accumulator to detect the pressure rise gradient, and sets the preset pressure rise gradient set value and the detected pressure rise gradient detection value. A pressure rise gradient detection circuit for stopping the operation of the warning delay circuit when the pressure rise gradient detected value is less than the pressure rise gradient set value by comparison is provided.

[0011]

In the warning device for the hydraulic brake booster according to the present invention, the warning delay circuit delays the operation of the warning circuit after the ignition switch is turned on for a predetermined time. On the other hand, the pressure rise gradient detection circuit detects the pressure rise gradient by detecting the pressure change per unit time of the accumulator after the ignition switch is turned on, and detects the pressure rise gradient set value set in advance and the detected pressure rise gradient. If the pressure rise gradient detection circuit determines that the pressure rise gradient detection value is greater than or equal to the pressure rise gradient set value, the system determines that the system is operating normally and allows the warning delay circuit to operate. The delay circuit delays the operation of the warning circuit. Also, if the pressure rise gradient detection circuit determines that the pressure rise gradient detection value is less than the pressure rise gradient set value, it is determined that the system is abnormal and the warning delay circuit operation is stopped within the predetermined time after the ignition switch is turned on. Even if there is, the warning circuit is released from the warning delay circuit operation and the warning circuit is activated, and a warning is issued when the hydraulic pressure in the accumulator drops.

[0012]

The present invention will be described below with reference to the illustrated embodiments.
1 is a system diagram showing the overall configuration of a hydraulic brake booster according to a first embodiment of the present invention, and FIG. 2 is a circuit diagram showing each circuit of a warning device of the hydraulic brake booster shown in FIG. 3 is a circuit diagram showing the pressure rise gradient detection circuit of FIG. 2, FIG. 6 is a graph of a pressure rise curve showing the pressure rise gradient of the hydraulic pressure in the accumulator, and FIG. 7 is a pressure rise gradient detection circuit of the warning device of FIG. 3 is a flowchart showing the operation of FIG. In the hydraulic brake booster, as shown in FIG. 1, the pedaling force applied to the brake pedal 2 is increased via the hydraulic booster 104 and transmitted to the master cylinder 6 to generate the hydraulic pressure generated in the master cylinder 6. Is sent to the wheel cylinders 8 and 10 of the front and rear wheels to perform a braking action.

As shown in FIG. 1, the hydraulic booster 104 accumulates the oil in the hydraulic booster tank 128 in the accumulator 116 by the pump 114 driven by the motor 112, and is operated by the hydraulic pressure of the accumulator 116. It A motor operating pressure switch 122, a warning pressure switch 124 and a check valve 118 are provided between the accumulator 116 and the pump 114. 101 indicates a filter.

The relief valve 105 is provided between the hydraulic pressure introduction side passage 106 between the accumulator 116 and the hydraulic pressure booster 104, and the supply side passage 107 connected to the hydraulic pressure booster tank 128. Introductory passage 10
When the hydraulic pressure of 6 exceeds a predetermined value, the hydraulic pressure is changed to the supply side passage 107.
It is supposed to escape.

The warning device for the hydraulic brake booster according to the first embodiment, as shown in FIG. 2, has a motor operating circuit (pump drive circuit) C11 and a warning circuit C12.
And a warning circuit C12 after the ignition switch 132 is turned on.
Warning delay circuit C14 for delaying energization of the device for a predetermined time t1
Is connected to the warning delay circuit C14 so that it can be electrically switched ON / OFF, and detects a pressure change of the accumulator 116 to detect a pressure increase gradient of the hydraulic pressure of the accumulator 116, and set a preset pressure increase gradient. The pressure increase gradient detection circuit C15 is configured to determine by comparing the set value Ip with the detected pressure increase gradient detection value Ia.

The motor operating circuit C11 is electrically connected to the battery 111 via an ignition switch 132. The motor operating circuit C11 includes a motor operating pressure switch 122 and a motor relay 123. As shown in FIG. 6, the motor operating pressure switch 122 is turned on when the hydraulic pressure of the accumulator 116 is released and the hydraulic pressure falls below a set value Pc (for example, Pc = 90 kg / cm ² ), and the motor relay 123 is turned on. ON,
The motor 112 is operated to drive the pump 114. When the hydraulic pressure rises to the set pressure Pn and the pressure accumulation is completed, the hydraulic pressure is turned off and the motor 112 is stopped.

As shown in FIG. 2, the warning circuit C12 has a battery 11 via an ignition switch 132.
Electrically connected to 1. The warning circuit C12 includes a warning pressure switch 124, a warning relay 125, a warning buzzer (warning device) 130, and a warning lamp (warning device) 131.
It is configured with. The warning circuit C12 is a rectifier 138.
Is electrically connected to the motor operating circuit C11 via.
The warning pressure switch 124 is always turned on, and as shown in FIG. 6, the hydraulic pressure of the accumulator 116 is changed to the pump 1
Hydraulic pressure P set lower than hydraulic pressure Pc for operating 12
Turns off when it reaches w (for example, Pw = 65kg / c
m ² ). The warning circuit C12 includes the warning pressure switch 1
When 24 is turned off, the warning relay 125 is demagnetized, a warning is issued by the warning buzzer 130 and the warning lamp 131, and when the hydraulic pressure of the accumulator 116 exceeds Pw, the warning pressure switch 124 is turned on to excite the warning relay 125, It is supposed to stop the warning.

As shown in FIG. 2, the warning delay circuit C14 includes a battery 11 via an ignition switch 132.
Electrically connected to 1. The warning delay circuit C14 includes a warning delay timer 140 and a delay timer relay 141. When the ignition switch 132 is turned on and energized, the delay timer 140 excites the preset predetermined time t1 delay timer relay 141 and turns off the relay contact. Delay timer relay 141 is warning relay 1
25, it is provided between the earth side (-side) and turns off the relay contact when the relay coil is energized, disconnects the electrical connection between the warning relay 125 and the earth side, and turns on the relay coil when degaussed. To electrically connect the warning relay 125 and the ground side. In this way, the warning delay circuit C14 delays energization of the warning circuit C12 by a predetermined time t1 after the ignition switch 132 is turned on. The predetermined time t1 preset in the warning delay timer 140 is, for example,
The vehicle is parked for a long time, a minute liquid leak occurs from the valve etc. inside the hydraulic brake booster, and the accumulator 1
When the hydraulic pressure accumulated in 16 escapes to the hydraulic booster tank 128 and the hydraulic pressure of the accumulator 116 decreases,
This is the time required from the start of the engine until the accumulation of pressure in the accumulator 116 is completed and the normal boosting function is restored. In the present embodiment, as shown in FIG. 6, the gas pressure of the accumulator 116 (that is, the accumulator 116).
It takes about 35 seconds to rise from a low pressure of 40 kg / cm ² to a gas pressure (115 kg / cm ² ) sufficient to obtain a normal boosting function, and the predetermined time t1 is about 35 I try to secure more than a second.

As shown in FIG. 2, the pressure rise gradient detection circuit C15 is electrically connected to the battery 111 via an ignition switch 132. The pressure rise gradient detection circuit C15 includes a pressure rise gradient detection unit 150 and a pressure sensor 1.
51 and a switching circuit 152. The pressure sensor 151 is provided in the pressure rise gradient detection unit 150.
Are electrically connected. The pressure sensor 151 detects the hydraulic pressure of the accumulator 116 and sends a detection signal to the pressure rise gradient detection unit 150. A switching circuit 152 is electrically connected to the pressure rise gradient detection unit 150. The switching circuit 152 includes a delay timer relay 1
The excitation coil of the delay timer relay 141 is electrically connected to the excitation coil of No. 41 and turns on / off the excitation coil of the delay timer relay 141 based on the ON / OFF switching signal from the pressure rise gradient detection unit 150.

As shown in FIG. 3, the pressure rise gradient detecting section 150 comprises a power supply circuit 153, a timer 154, an arithmetic circuit 155 and an amplifier circuit 156. The amplifier circuit 156 amplifies the signal of the hydraulic pressure of the accumulator 116 detected by the strain gauge 151A of the pressure sensor 151 and sends it to the arithmetic circuit 155. The arithmetic circuit 155 is
The detection signal input from the amplifier circuit 156 is calculated, and the pressure rise gradient detection value Ia of the accumulator 116 at the set time Δt set by the timer 154 is detected. As used herein, the pressure increase gradient of the accumulator 116 means the increase amount ΔP of the hydraulic pressure of the accumulator 116 per set time Δt set by the timer 154 when the pump 114 is operating, as shown in FIG. This is represented by ΔP / Δt. Also, the arithmetic circuit 1
At 55, a pressure increase gradient set value Ip when the pressure is normally stored in the accumulator 116 is preset,
Remembered.

The arithmetic circuit 155 has a preset pressure increase gradient set value Ip and a detected pressure increase gradient detected value Ia.
When the pressure rise gradient detection value Ia is less than the pressure rise gradient set value Ip, the switching circuit 152
An OFF signal is sent to the switching circuit 152 to turn it off. Here, when the pressure increase gradient detection value Ia is equal to or more than the pressure increase gradient set value Ip, it is determined that the pressure accumulation in the accumulator 116 by the pump 114 is normally performed, and the pressure increase gradient detection value Ia is the pressure increase gradient. Set value I
When it is less than p, the accumulation of pressure in the accumulator 116 is delayed, and it is determined that some abnormality has occurred in the pump 114, the motor 112, or the accumulator 116. The switching circuit 152 is an arithmetic circuit 155.
The energization of the exciting coil of the delay timer relay 141 is turned on / off based on the ON / OFF signal from the.

Therefore, the pressure rise gradient detection circuit C15 is
When the ignition switch 132 is turned on, when the pressure change of the accumulator 116 is detected and the pressure increase gradient detection value Ia is equal to or higher than the pressure increase gradient set value Ip, the pressure accumulation system is determined to be normal, and the switching circuit 152 causes the delay timer relay 141 to operate. Since the exciting coil of can be energized,
The operation of the warning delay circuit C14 is ensured, and the warning delay timer 1
When the relay contact of the delay timer relay 141 is turned off according to the operation of 40, the warning pressure switch 124
The operation of the warning circuit C12 is stopped irrespective of ON / OFF of.

By the way, the pressure rise gradient detecting circuit C15
Indicates that the pressure rise gradient detection value Ia is the pressure rise gradient set value Ip.
If it is less than the above, the pressure accumulation system is judged to be abnormal, and the energizing of the exciting coil of the delay timer relay 141 is turned off by the switching circuit 152.
The warning circuit C12 is turned on when the warning pressure switch 124 is turned on. That is,
When the pressure increase gradient detection value Ia is less than the pressure increase gradient set value Ip after the ignition switch 132 is turned on, the pressure increase gradient detection circuit C15 stops the operation of the warning delay circuit C14 and turns on the warning pressure switch 124. The warning circuit C12 is operated according to the OFF state.

Next, the operation of the warning device of the hydraulic brake booster according to the first embodiment will be described with reference to FIGS. 2, 6 and 7 based on the operation of the pressure rise gradient detection circuit C15. . As shown in FIG. 2, when the ignition switch 132 is turned on, each circuit C11, C12, C1
4, C15 is energized. The motor operating pressure switch 122 senses the hydraulic pressure P of the accumulator 116, and is turned on when the hydraulic pressure of the accumulator 116 falls below a predetermined value Pc to operate the motor operating circuit C11 to operate the motor 112 to pump the pump. 114 is driven. At this time, as shown in FIG. 6, when the hydraulic pressure of the accumulator 116 is lower than the predetermined value Pc and lower than the hydraulic pressure Pw due to long-time parking or the like, the warning pressure of the warning circuit C12 is set. The switch 124 is turned off, the warning relay 125 is demagnetized, and the relay contact of the warning relay 125 is turned on. On the other hand, the warning delay timer 140 of the warning delay circuit C14, after the ignition switch 132 is turned on,
The excitation coil of the delay timer relay 141 is excited for a predetermined time t1, and the relay contact of the delay timer relay 141 is turned off.
To do. Therefore, ON / O of the relay contact of the warning relay 125
The operation of the warning circuit C12 is stopped regardless of FF. Then, the warning delay timer 140 demagnetizes the delay timer relay 141 after a predetermined time t1 has elapsed, and turns on the relay contact.

In the warning device for the hydraulic brake booster according to the first embodiment, as shown in FIG. 7, the ignition switch 132 is turned on at S1 and the warning delay circuit C is turned on at S2.
When the warning delay timer 140 of 14 is turned on, the delay timer relay 141 is turned on in S3. That is, the delay timer relay 141 is excited and the relay contact is turned off. Next, in S4, when the pressure increase gradient detection circuit C15 detects the change in the hydraulic pressure of the accumulator 116 by the pressure sensor 151, the pressure increase gradient set value I set in advance is set.
It is determined by comparing p with the detected pressure rise gradient detection value Ia. When the pressure increase gradient detection unit 150 determines that the pressure increase gradient detection value Ia is less than the pressure increase gradient set value Ip in S4, the pressure increase gradient detection unit 150 is determined in S5.
Turns off the switching circuit 152, turns on the relay contact of the delay timer relay 141, and ends the step in S6. After that, when the relay contact of the warning relay 125 is turned on and the warning circuit C12 operates, a warning is issued. Therefore, the warning circuit C12 operates according to ON / OFF of the warning pressure switch 124 regardless of the operation of the warning delay circuit C14 even within the predetermined time t1, and when the warning pressure switch 124 is OFF. The warning buzzer 130 and the warning lamp 131 warn the driver.

Further, as shown in FIG. 7, when the pressure increase gradient detection unit 150 determines in step S4 that the pressure increase gradient detection value Ia is greater than or equal to the pressure increase gradient set value Ip, the operation time of the warning delay timer 140 is determined in step S7. It is determined whether or not it is the predetermined time t1 or more. When it is determined in S7 that the operation time of the warning delay timer 140 is the predetermined time t1 or less, the process returns to S4. S
When it is determined in 7 that the operation time of the warning delay timer 140 is the predetermined time t1 or more, in S8, the delay timer relay 141 is demagnetized by the warning delay timer 140 and the relay contact is turned on.
Then, the step is ended in S6. After that, when the relay contact of the warning relay 125 is turned on and the warning circuit C12 operates, a warning is issued. Therefore, when the pressure accumulation system is determined to be normal, the warning circuit C12 is prevented from operating by the operation of the warning delay circuit C14 for a predetermined time t1.
Regardless of ON / OFF of the warning pressure switch 124,
No warning is given to the driver.

As described above, in the warning device for the hydraulic brake booster according to the first embodiment, the accumulator 11 is used.
When there is an abnormality in the increase in the hydraulic pressure of 6, the warning circuit C12 is operated with priority over the operation of the warning delay circuit C14, and the driver can be quickly warned. Furthermore, if the hydraulic pressure rise of the accumulator 116 is normal, the warning delay circuit C
Since the operation of the warning circuit C12 is secured and the operation of the warning circuit C12 is stopped for a predetermined time t1 after the ignition switch 132 is turned on, the driver's anxiety can be eliminated by removing unnecessary warnings.

Next, a warning device for a hydraulic brake booster according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 8. In the figure, those parts which are the same as or correspond to those of the first embodiment are designated by the same reference numerals, and a description thereof will be omitted. As shown in FIG. 4, the warning device of the hydraulic brake booster according to the second embodiment of the present invention includes a motor operating circuit C11, a warning circuit C12, a pressure sensor 151, and a controller 25.
0 and a delay timer relay 241.
The controller 250 is configured by integrally providing a pressure increase gradient detection circuit C25 and a warning delay timer 240.

When the pressure increase gradient detection circuit C25 detects the pressure change of the accumulator 116 by the pressure sensor 151 and detects the pressure increase gradient ΔP / Δt of the hydraulic pressure of the accumulator 116, the controller 250 informs the pressure increase gradient detection circuit C25. The preset and stored pressure rise gradient set value Ip and the detected pressure rise gradient detection value Ia ₁
To Ia _n ( _n is an integer of 1 or more) are compared to make a determination. In this embodiment, the comparison with the pressure increase gradient set value Ip is performed three times or more. The controller 250 then detects the pressure increase gradient detection values Ia _{1 to} I detected at each set time t3 set by the timer A1.
When at least one value of a _n is equal to or more than the pressure increase gradient set value Ip, the relay contact of the delay timer relay 241 is kept OFF, and the operation of the warning circuit C12 is set for a predetermined time t2 (t2> t3). ) Stop. Further, the controller 250 is configured to detect each pressure rise gradient detection value Ia.
₁ ～Ia If _n is less than the pressure increase gradient set value Ip all to stop the operation of the warning delay timer 240 turns ON the relay contacts of the delay timer relay 241 causes the warning circuit C12 operatively. The predetermined time t2 referred to here is the accumulator 1 due to liquid leakage inside the hydraulic brake booster.
This is the time required from the start of the engine to the completion of the pressure accumulation in the accumulator 116 and the return to the normal boosting function when the hydraulic pressure of 16 is reduced. Also, the set time t3
Is the pressure rise gradient Δ when accumulating pressure in the accumulator 116.
This is a time preset in the timer A1 for detecting P / Δt.

Next, the operation of the warning device of the hydraulic brake booster according to the second embodiment will be described with reference to the controller 25.
The operation of 0 will be described with reference to FIGS. 4 and 8.
In this embodiment, the controller 250 sets the set time t3.
Pressure rise gradient detection values Ia ₁ , Ia ₂ ... Ia _n
After 3 times or more, the pressure rise gradient detection values Ia ₁ , I
If at least one of a ₂ ... Ia _n is equal to or higher than the pressure increase gradient set value Ip, the pressure accumulation system is normal, and all of the pressure increase gradient detection values Ia ₁ , Ia ₂ ... Ia _n are pressure increase gradients. If it is less than the set value Ip, the pressure accumulation system is judged to be abnormal.

As shown in FIG. 8, the controller 250 turns on the ignition switch 132 in S10,
When the warning delay timer 240 is turned on in S11, the delay timer relay 241 is excited and the relay contact is turned off in S12.

Next, the pressure increase gradient detection value of the operating frequency N and the above pressure increase gradient set value Ip of the timer A1 which measures the pressure increase gradient [Delta] P / Delta] t detected every set time t3 at S13 Ia ₁ ~Ia _n The counters that measure the number of appearances M of the and are respectively reset. The timer A1 is reset in S14, the timer A1 is counted up in S15, and it is determined in S16 whether the operating time of the timer A1 is the preset time t3 or more. When the operating time of the timer A1 is less than the set time t3 in S16, the process returns to S15. The operation time of the timer A1 is set time t3 in S16.
In the above case, the operation number N of the timer A1 is counted up in S17, the pressure increase gradient detection value Ia ₁ detected in S18 is compared with the pressure increase gradient set value Ip, and the pressure increase gradient detection value Ia ₁ is calculated as the pressure. When the value is equal to or higher than the rising gradient set value Ip, the number of times M of appearance of the pressure rising gradient detected value Ia ₁ is counted up in S19, and the number of times N of operation of the timer A1 is N in S20.
Is judged three times or more. When the pressure increase gradient detection value Ia ₁ is less than the pressure increase gradient set value Ip in S18, S2
Skip to 0. When the number of times N the timer A1 is operated is less than 3 in S20, the process returns to S14. Timer A1 at S20
If the number of times N of operation is 3 or more, it is determined in S21 whether or not the pressure increase gradient detection value Ia ₁ of the pressure increase gradient set value Ip or more is 1 or more. If Occurrences M of rate of pressure rise setting value Ip or more pressure increase gradient detection value Ia ₁ ~Ia _n is determined to 1 or more in S21 (i.e. accumulator 1
16 is normal), the process proceeds to S22, and it is determined in S22 whether the operation time of the delay timer 240 is the predetermined time t2 or more. If the operation time of the delay timer 240 is less than the predetermined time t2 in S22, the process returns to S22 and is repeated until the operation time of the delay timer 240 exceeds the predetermined time t2. When the operation time of the delay timer 240 is longer than the predetermined time t2 in S22, the energization of the exciting coil of the delay timer relay 241 is turned off in S23, the relay contact of the delay timer relay 241 is turned on, and the step is finished in S24. After that, when the relay contact of the warning relay 125 is turned on and the warning circuit C12 operates, a warning is issued.

Further, if the number of occurrences M of the rate of pressure rise setting value Ip or more pressure increase gradient detection value Ia ₁ ~Ia _n is determined to less than 1 in S21, i.e. all pressure increase gradient detection value Ia ₁ ～Ia _When it is determined that _n is less than the pressure increase gradient set value Ip (the pressure accumulation system of the accumulator 116 is abnormal), the switching circuit 152 of the pressure increase gradient detection circuit C25 is turned off in S25, and the delay timer relay 2
Demagnetize 41 and turn on the relay contact. Therefore, when the pressure accumulation system of the accumulator 116 is abnormal, the delay timer relay 24 is given priority over the operation of the warning delay timer 240.
Since the relay contact 1 is turned on, a warning is issued when the warning circuit C12 operates.

As described above, in the warning device for the hydraulic brake booster according to the second embodiment, the brake pedal 2 is immediately depressed after the ignition switch 132 is turned on,
Even if the consume fluid pressure in the accumulator 116 can determine the normal or abnormal pressure accumulator system from a plurality of pressure gradient detected value Ia ₁ ~Ia _n more precisely, abnormal fluid pressure increase in Akyureta 116 In this case, the warning circuit C12 can be operated in priority to the operation of the warning delay timer 240, and the driver can be quickly warned.
Further, if the hydraulic pressure rise of the accumulator 116 is normal, the warning delay timer 240 is activated to activate the warning circuit C1.
Since the operation of No. 2 can be stopped for a predetermined time t2 after the ignition switch 132 is turned on, the driver's anxiety can be eliminated.

FIG. 9 shows a modified example of the warning device of the hydraulic brake booster according to the second embodiment, in which the function of the warning delay timer 240 is set by using the timer A2 a plurality of times (5 in this modified example). It is replaced by operating it. In the warning device of the hydraulic brake booster according to the above modification, the warning device shown in FIG.
As shown in, the controller 350 is configured by integrally providing the pressure increase gradient detection circuit C25 and the timer A2. This hydraulic brake booster includes a controller 35
As a result of 0, the pressure rise gradient detection value Ia for each set time t5
_1, Ia ₂ · · · Ia _n after determining more than three times as long at least one pressure increase gradient set value Ip or more of the pressure increase gradient detection value _{Ia 1, Ia 2 ··· Ia n} , accumulator system Is normal, pressure rise gradient detection values Ia ₁ , Ia ₂ ·
.. If all of Ia _n are less than the pressure increase gradient set value Ip, the pressure accumulation system is determined to be abnormal. When it is determined that the pressure accumulation system is normal, after the ignition switch 132 is turned on, the time obtained by adding five times the number of times of operation Na at which the timer A2 operates at the set time t5 is set as the predetermined time t6, and the predetermined time t6 ( t6 = t
During 5 × 5), the delay timer relay 241 is excited to turn off the relay contact. When it is determined that the pressure accumulation system is abnormal, the delay timer relay 241 is demagnetized and the relay contact is opened even within the predetermined time t6.
When turned on, the warning circuit C12 is operated.

Next, the operation of the warning device of the hydraulic brake booster according to the above modification will be described with reference to FIGS. 4 and 9. The controller 350, as shown in FIG.
Ignition switch 132 is turned on in S30, and S3
At 1, the timer A2 is turned on, the exciting coil of the delay timer relay 241 is energized, and the relay contact is turned off.

Next, the pressure increase gradient detection value operation number Na and the above pressure increase gradient set value Ip of the timer A2 which measures the pressure increase gradient [Delta] P / Delta] t detected every set time t5 in S32 Ia ₁ ~Ia _n The counters that respectively measure the number of appearances Ma and are reset. The timer A2 is reset in S33, the timer A2 is counted up in S34, and it is determined in S35 whether the operating time of the timer A2 is the preset time t5 or more. If the operation time of the timer A2 is less than or equal to the set time t5 in S35, S34
Return to. If the operation time of the timer A2 is equal to or longer than the set time t5 in S35, the operation number Na of the timer A2 is counted up in S36, and it is determined in S37 whether the operation number of the timer A2 is 5 times or more. When it is determined in S37 that the number of times the timer A2 has operated is five or more, the process skips to S42, the energization of the exciting coil of the delay timer relay 241 is turned off to turn on the relay contact in S42, and the step is finished in S43. At this time, the warning pressure switch 124 is turned on.
The warning circuit C12 is operable according to / OFF.

Further, at S37, the number of times of operation of the timer A2 Na
Is determined to be less than 5 times, the pressure increase gradient detection value Ia ₁ detected in S38 is compared with the pressure increase gradient setting value Ip, and the pressure increase gradient detection value Ia ₁ is greater than or equal to the pressure increase gradient setting value Ip. In this case, the number of appearances Ma of the pressure increase gradient detection value Ia _{1 which} is equal to or higher than the pressure increase gradient set value Ip is counted up in S39, and it is determined in S40 whether the number of times Na of operation of the timer A2 is 3 or more. In S38, the pressure rise gradient detection value I
If a ₁ is less than the pressure increase gradient set value Ip, the process skips to S40. When the number of times of operation Na of the timer A2 is less than 3 times in S40, the process returns to S33. When the number of operations Na of the timer A2 is 3 or more in S40, it is determined in S41 whether the number of appearances Ma of the pressure increase gradient detection value Ia ₁ equal to or higher than the pressure increase gradient set value Ip is 1 or more. Rate of pressure rise detection value of the above pressure increase gradient set value Ip at S41 Ia ₁ ~Ia _n
When it is determined that the number of appearances Ma of 1 is 1 or more (that is, the pressure accumulation system of the accumulator 116 is normal), S33
Then, the steps from S33 to S41 are repeated. That is, within a predetermined time t6 (the number of times the timer A2 has operated N
(a is less than 5 times) and the pressure accumulation system of the accumulator 116 is normal, the step S42 is not reached and the relay contact of the delay timer relay 241 is OFF.
It remains.

[0039] If the number of occurrences Ma pressure increase gradient set value Ip or more pressure increase gradient detection value Ia ₁ ~Ia _n is determined to less than 1 in S41, that is, all of the pressure increase gradient detection value Ia ₁ ~Ia _n When it is determined that the pressure rise gradient setting value Ip is less than (the accumulator 116 pressure accumulation system is abnormal), the delay timer relay 241 is demagnetized to turn on the relay contact in S42, and the step is ended in S43. After that, the warning circuit C12 can be operated according to ON / OFF of the warning pressure switch 124.

[0040] As such, the above warning device of the hydraulic brake booster according to a modification of the second embodiment, a warning delay timer timer A2 for detecting the respective pressure increase gradient detection value Ia ₁ ~Ia _n Since it is used, the number of parts can be reduced. In the above embodiment, either comparing determines three or more times the rate of pressure rise detection value Ia ₁ ~Ia _n, also the warning delay time is based on the whether the timer A2 is activated 5 times, each number It is needless to say that is not limited to these and can be appropriately selected according to the accumulator capacity, pump capacity, etc. of the accumulator.

Next, a warning device for a hydraulic brake booster according to a third embodiment of the present invention will be described with reference to FIGS. 5 and 10. In the figure, parts that are the same as or correspond to those in each of the above-described embodiments are assigned the same reference numerals and explanations thereof are omitted. As shown in FIG. 5, a warning device for a hydraulic brake booster according to a third embodiment of the present invention includes a motor operating circuit C11,
A warning circuit C12, a pressure sensor 151, a controller 450, and a delay timer relay 241 are provided, and a brake switch 401 and a brake lamp 402 are electrically connected to the battery 111, and the brake switch 401 is connected to the controller 450. It is electrically connected. The brake switch 401 as a switching circuit is turned on to turn on the brake lamp 402 when a pedaling force is applied to the brake pedal 2.

The controller 450 is constructed by integrally providing a pressure rise gradient detecting circuit C45 and a warning delay timer 440. The brake switch 401 is electrically connected to the pressure increase gradient detection circuit C45, and activates the pressure increase gradient detection circuit C45 according to whether the brake is operated or not.
Turn on / off. That is, the controller 450 turns on the brake switch 401 after turning on the ignition switch 132.
Is turned on, the operation of the pressure increase gradient detection circuit C45 is stopped, and when the brake switch 401 is turned off, the pressure increase gradient detection circuit C45 is operated.

Next, the operation of the warning device of the hydraulic brake booster according to the third embodiment will be described with reference to the controller 45.
The operation of 0 will be described with reference to FIGS. 5 and 10. As shown in FIG. 10, the controller 450 of the hydraulic brake booster according to the third embodiment, when the ignition switch 132 is turned on in S50 and the warning delay timer 440 is turned on in S51, is delayed in S52. Timer relay 2
41 is excited and the relay contact turns off. Next, in S53, the flag is reset, and in S54, the brake switch 401
ON / OFF is determined. In S54, the brake switch 40
When 1 is OFF, in S55 the pressure rise gradient detection circuit C45
When the pressure sensor 151 detects a change in hydraulic pressure of the accumulator 116, the pressure sensor 151 compares the preset pressure increase gradient set value Ip with the detected pressure increase gradient detection value Ib to make a determination. When the pressure increase gradient detection circuit C45 determines that the pressure increase gradient detection value Ib is less than the pressure increase gradient setting value Ip in S55, the switching circuit 152 of the pressure increase gradient detection circuit C45 is turned off in S56, and the delay timer relay 241 Demagnetizes and turns on the relay contact, S
The step ends at 57. If the pressure increase gradient detection circuit C45 determines in step S55 that the pressure increase gradient detection value Ib is greater than or equal to the pressure increase gradient set value Ip, the process skips to step S59 described below.

If the brake switch 401 is ON in S54, the flag is set in S58, and the delay timer 4 is set in S59.
It is determined whether the operation time of 40 is the predetermined time t6 or more. In S59, the operation time of the delay timer 440 is the predetermined time t
If 6 or more, the delay timer relay 241 is demagnetized and the relay contact is turned on in S60. If the operation time of the delay timer 440 is less than the predetermined time t6 in S59, it is determined whether or not the flag is set in S61. If the flag is set, the process returns to S59, and if the flag is not set, the process proceeds to S54. Return. Further, in S55, it is determined that the pressure increase gradient detection value Ib is not less than the pressure increase gradient set value Ip, and S5
If the operation time of the delay timer 240 is less than the predetermined time t6 in 9, the flag is not set, and therefore the steps S61 to S61 are performed.
Return to 54.

As described above, in the warning device for the hydraulic brake booster according to the third embodiment, the brake switch 401
The pressure rise gradient detection circuit C45 operates only when the
When the brake switch 401 is turned on, the pressure increase gradient detection circuit C45 is not activated. Therefore, when the brake pedal 2 is stepped on immediately after the ignition switch 132 is turned on and the hydraulic pressure of the accumulator 116 is consumed, the pressure increase gradient ΔP / Δt becomes smaller and the detected pressure increase gradient detection value Ib becomes the pressure increase gradient. Even if it becomes less than the set value Ip, it is not judged as an abnormality of the pressure accumulating system. Therefore, even if the brake is actuated, the normality / abnormality of the pressure accumulating system can be accurately distinguished and determined, and the malfunction can be prevented.

[0046]

As described above, according to the present invention, even if the warning circuit is inactive for a predetermined time after the engine is started, it is possible to determine whether or not there is a system abnormality by detecting the pressure accumulation state in the accumulator. In the event of an abnormality, the warning circuit can be released from the inoperative state and the driver can be immediately warned, so that the reliability of the warning can be improved and the safety can be improved.

[Brief description of drawings]

FIG. 1 is a system diagram showing an overall configuration of a hydraulic brake booster according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing each circuit of a warning device of the hydraulic brake booster of FIG.

FIG. 3 is a circuit diagram showing the pressure rise gradient detection circuit of FIG.

FIG. 4 is a circuit diagram showing each circuit of a warning device of a hydraulic brake booster according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing each circuit of a warning device for a hydraulic brake booster according to a modification of the second embodiment of the present invention.

FIG. 6 is a graph of a pressure rise curve showing a pressure rise gradient of the hydraulic pressure in the accumulator.

FIG. 7 is a flowchart showing the operation of the pressure rise gradient detection circuit of the warning device of the hydraulic brake booster according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the controller of the hydraulic brake booster according to the second embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the controller of the hydraulic brake booster according to the modification of the second embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the controller of the hydraulic brake booster according to the third embodiment of the present invention.

FIG. 11 is a circuit diagram of a warning device of a conventional hydraulic brake booster.

FIG. 12 is a circuit diagram of a warning device of a conventional hydraulic brake booster.

[Explanation of symbols]

112 motor 116 accumulator 132 ignition switch C11 motor actuation circuit C12 warning circuit C14 warning delay circuit C15, C25, C35, C45 pressure increase gradient detecting circuit Ip pressure increase gradient setting value Ia, Ia ₁ ~Ia _n, Ib pressure increase gradient detection value

Claims (3)

[Claims] 1. A pump driven by a motor, an accumulator that accumulates pressure by the pump, a hydraulic booster that boosts a brake pedal force at the time of braking by a hydraulic pressure of the accumulator to operate a master cylinder, and an ignition. It is electrically connected to the battery via a switch, and turns on when the hydraulic pressure of the accumulator drops to a specified value to operate the motor, and turns off when the accumulated pressure reaches the specified value to stop the motor. After the ignition switch is turned on, in the hydraulic brake booster equipped with a motor operating circuit that activates and a warning circuit that issues a warning with a warning device when the hydraulic pressure of the accumulator drops to a predetermined pressure below the pressure that operates the motor. A warning delay circuit that delays the operation of the above warning circuit for a predetermined time and electrically connected to this warning delay circuit The pressure rise gradient is detected by detecting the pressure change per unit time of the accumulator, and the pressure rise gradient is detected by comparing the preset pressure rise gradient set value with the detected pressure rise gradient detection value. A warning device for a hydraulic brake booster, comprising: a pressure increase gradient detection circuit for stopping the operation of the warning delay circuit when the detected value is less than the pressure increase gradient set value. 2. The pressure rise gradient detection circuit comprises at least one
The above pressure rise gradients are detected, and the detected pressure rise gradient detection values and the preset pressure rise gradient set values are compared to determine each, and all the pressure rise gradient detected values are all pressure rise gradient set values. 2. The warning device for the hydraulic brake booster according to claim 1, wherein the warning delay circuit is stopped when it is less than a predetermined value. 3. A switching circuit electrically connected to the pressure rise gradient detection circuit and provided with a switching circuit for turning ON / OFF the operation of the pressure rise gradient detection circuit depending on whether the brake is operated or not. Item 3. A warning device for a hydraulic brake booster according to item 1 or 2.