JP3427479B2 - Control circuit in hydraulic booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a motor driven by an electric motor.
Supply working fluid of a predetermined pressure from the pump to the fluid pressure booster.
A hydraulic booster adapted to supply
Even if one of the energizing systems of the motor is deactivated,
Hydraulic booster that energizes the electric motor in the system
And a control circuit in the device. [0002] 2. Description of the Related Art A pump driven by a conventional electric motor
To supply the working fluid at a predetermined pressure to the hydraulic pressure booster.
The control circuit of the hydraulic booster shown in FIG.
There are known road configurations. This control circuit
Pump for supplying a working fluid of a predetermined pressure to a pressure booster
One end of an electric motor M for driving the motor is connected to a motor energizing relay R.
Connected to the positive electrode side of battery B via M normally open contact RMa
And the other end is grounded, and the negative side of battery B is grounded.
Have been. On the other hand, the excitation coil of the motor energizing relay RM
One end of RMb is connected via an ignition switch IG
On the positive electrode side of battery B, the other end is a motor drive pressure switch.
And is grounded through the switch SM. In addition, the Ignit
Point C between the switch IG and the exciting coil RMb
Is a parallel circuit of an alarm buzzer KB and an alarm light KL and an alarm
Grounded via the normally closed contact RKa of the operating relay RK,
One end of the excitation coil RKb of the relay RK for alarm activation is an alarm
Connected to the connection point C via an operating pressure switch SK
And the other end is grounded. Here, a motor driving pressure switch SM
Detects the supply pressure to the hydraulic booster (not shown) and
The force detection value is within the range that allows normal operation of the hydraulic booster.
Is set to a value near the lower limit of the normal operable range.
When the pressure is lower than the set pressure, it is turned on and the detected pressure value is
When the value becomes equal to or higher than the upper limit value of the always operable range, it turns off.
It is set to be. Also, the pressure switch for alarm activation
SK detects the supply pressure to the hydraulic booster and determines the pressure.
The force detection value is set lower than the first set pressure;
If the pressure is higher than the second set pressure,
When the force detection value falls below the second set pressure, it will turn off.
Is set. Then, the ignition switch IG is turned off.
When the engine is started with the
When the supply pressure is within the normal operating range, the motor
The drive pressure switch SM is off and the motor
Without energizing the exciting coil RMb of the energizing relay RM,
Since the normally open contact RMa is off, the electric motor M is stopped.
It has been stopped. Pressure switch for alarm activation
Since SK is in the ON state, the activation of the alarm activation relay RK is performed.
The magnetic coil RKb is energized and its contact RKa is
The warning buzzer KB and the warning light KL are also
Maintain the working state. [0005] In this state, for example, the vehicle is started and run.
To the braking state and depress the brake pedal during this time.
Operation to operate the hydraulic booster,
When the supply pressure to the booster drops below the first set pressure,
The motor driving pressure switch SM is turned on.
And the excitation coil RMb of the motor energizing relay RM is energized.
Then, the contact RMa is closed and the electric motor M is driven.
Hydraulic booster by the pressure oil discharged from the pump
Supply pressure to the normal operation range. On the other hand, the motor driving pressure switch SM
Is abnormal, or the motor energizing relay RM
If the relay RM does not operate due to an abnormality in
Even if the supply pressure falls below the first set pressure, the electric motor M
Is not driven, the supply pressure is low every time the braking operation is performed.
If the pressure falls below the second set pressure, the alarm activation pressure
The force switch SK is turned off. Because of this, alarm activation
The excitation coil RKb of the relay RK is turned off,
Since the contact RKa is closed, the alarm buzzer KB and the alarm
The notification light KL operates to notify the abnormal decrease in the supply pressure. [0007] SUMMARY OF THE INVENTION
In the control circuit of the conventional hydraulic booster,
If the current supply system of the motor M is
System, the contact R of this motor energizing relay RM
Ma has poor conduction or opens / closes this contact RMa
The energization path of the excitation coil RMb is disconnected or the excitation coil
Pressure switch SM for motor drive in the current path of
Or the excitation coil RMb is burned
Then, the motor energizing relay RM becomes inactive.
Electric motor M is not energized and supply pressure to hydraulic booster is different.
There is an unsolved problem that it always remains lower. There
Thus, the present invention has been made in view of the above-mentioned unsolved problems.
Even if one power supply system becomes inactive, other
Power supply to the electric motor by the power supply system to the hydraulic booster
Hydraulic booster that prevents abnormal lowering of supply pressure
The purpose is to provide a control circuit in the device
You. [0008] [MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
And a control circuit in the hydraulic booster according to claim 1.
Is a pump driven by an electric motor to the hydraulic pressure booster
Hydraulic booster that supplies working fluid at a predetermined pressure
In placeContacts are connected in parallel to the current path of the electric motor.
Inserted first and second relays and the fluid pressure booster
To detect that the supply pressure to the pressure becomes equal to or lower than the first set pressure.
A first pressure switch and a supply pressure to the fluid pressure booster
Became equal to or less than a second set pressure lower than the first set pressure.
At least a second pressure switch for detecting
The excitation coil of the first relay is connected to the first pressure switch.
Energization control by a switch and a second pressure switch,
The exciting coil of the second relay is connected to the second pressure switch.
Power supply system different from the first excitation coil
Energization controlledIt is characterized by the following. [0009] [0010] [0011] [0012] [0013] [0014] [0015] [0016][Action] Claim1In Hydraulic Booster Related to Air
In the circuit, the first pressure switch goes to the hydraulic booster
Detecting that the supply pressure of
The energization of the exciting coil of the first relay is controlled, and
The opening and closing of the contacts of the relay is controlled, and the energization of the electric motor is
Controlled. On the other hand, the second pressure switch sets the supply pressure to
Detecting that the pressure has become equal to or less than the second set pressure, the second relay
The excitation coil of the firstRelayDifferent from the excitation coil
To control energization in the power systemRelayExciting carp
Even if an abnormality occurs in the power supply system of theRelayExciter
The current is controlled to be applied to the contact of the second relay.
The opening and closing of the motor is controlled to control the energization of the electric motor,
Prevent abnormal decrease in supply pressure to body pressure booster. Further,,PreviousThe excitation coil of the first relay is
The current is also controlled by the second pressure switch.
As a result, the first pressure switch is damaged and supply to the hydraulic booster
Even if the supply pressure cannot be detected, the supply pressure is maintained at the second setting.
The second pressure switch detects that the pressure has become equal to or less than the constant pressure.
And energization control of the respective excitation coils of the first and second relays.
The opening and closing of each contact of the relay is controlled, and the energization of the electric motor is
Controlled. Therefore, in addition to the damage of the first pressure switch,
When the abnormality occurs in the excitation coil of the second relay
Indicates that the supply pressure has fallen below the second set pressure.
When the pressure switch detects, the excitation coil of the first relay
Is controlled to open and close the contacts of this relay.
Power supply to the hydraulic pressure booster controlled by energization of the electric motor
Prevent abnormal pressure drop. [0018] DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.
I will tell. FIG. 1 is a hydraulic circuit diagram showing one embodiment of the present invention.
is there. In the same figure, driven by an electric motor M
The suction side of the pump 2 for pressurizing the brake fluid is
Brake fluid as working fluid through the
Connected to the stored reservoir tank 8,
The discharge side of the pump 2 has a check valve 10, a high pressure hose 12,
Piping 14, high pressure hose 16, check valve 18, piping 20
The brake fluid by the brake fluid through these orders
Hydraulic booster as a hydraulic booster that boosts the pedaling force of the
Connected to the inlet port 26 of the
The return port 28 of the heater 24 is connected through a low pressure hose 30
And connected to the reservoir tank 8. The hydraulic booster 24 has a boosted booster.
Front brake not showing the depression force of the rake pedal 22
Master cylinder 36 to be transmitted to the system and rear brake system
Are linked. The hydraulic booster 24 is a brake pedal
When 22 is depressed, its inlet port 26
Uses the supplied high-pressure brake fluid for boosting.
After that, the brake fluid is released and the brake pedal 22 is released.
The return port 28 as low pressure brake fluid when
Is discharged to the reservoir tank 8. In addition, the hydraulic
Port 24 of the heater 24 and return port
28, the supply pressure of the hydraulic booster 24, that is, the pipe 2
When the zero pressure rises abnormally, the brake fluid is
A relief valve 38 for releasing into the bar tank 8 is inserted.
ing. Then, under the check valves 10 and 18,
Inflow pipes 14 and 20 have N_TwoGas is sealed and
First and second accumulators for accumulating pressurized brake fluid
The radiators 32 and 34 are connected. The first accumulator
The normal operation of the hydraulic booster 24 is provided to the
Possible supply pressure range of inlet port 26 side
At a pressure value slightly lower than the lower limit of the normal operating range.
For example, N_TwoGas is sealed and the hydraulic booster 24
The supply pressure to the inlet port 26 (hereinafter, the inlet supply pressure
Is within the normal operation range and the hydraulic booster 24
Is in a normal operating state, the first accumulator 32
Works effectively. In addition, the second accumulator 34
Is, for example, N_TwoGas is filled in the first accumulator 32
Lower than the pressure, for example, the operation abnormality of the hydraulic booster 24.
From the lower limit of the supply pressure on the inlet side of the hydraulic booster 24 immediately before
It is sealed at a slightly lower pressure value,
Inlet supply of hydraulic booster 24 for minimum operation
When the pressure is within the operable range when the pressure is abnormal, the second accumulation
The data 34 functions effectively. First and second accumulators 32 and 3
The hydraulic booster 24 is connected to the connection point between the pipe 4 and the pipes 14 and 20.
And pressure detection means for detecting the supply pressure on the inlet side
And a motor driving pressure switch as a second pressure switch.
Switch SM and a pressure switch SK for alarm activation are provided.
You. Here, the motor driving pressure switch SM is shown in FIG.
As shown, whether the supply pressure on the inlet side of the hydraulic booster 24 is normal or not.
The first setting of the value near the lower limit of the normal operation range
Constant pressure, for example 90 kg / cm^TwoIt will be in the on state when
The supply pressure on the inlet side rises and the
Near limit value, for example, 115 kg / cm^TwoOff when
It has a hysteresis characteristic to be in a state. The pressure switch SK for alarm operation is
Possible to operate when the supply pressure on the inlet side of the pressure booster 24 is reduced and abnormal
The second set pressure near the lower limit of the range, for example, 65 kg / cm
^TwoWhen it becomes below, it will be off state, and the inlet side supply pressure will rise
And a value near the upper limit of the operable range at the time of abnormality, for example, 80 kg /
cm^TwoWhen this occurs, the hysteresis characteristic that turns on
Have. Further, the pressure switch SK for alarm operation is
Pressure supply pressure of pressure booster 24 drops below a second set pressure
Warning buzzer 4 and warning light 5
The warning light 5 is provided in the reservoir tank 8.
Even if the liquid level warning switch 40 that is
It is configured to be turned on. Then, drive pump 2
The moving electric motor M is driven by the control circuit shown in FIG.
Controlled. In the figure, the negative side of the battery B is grounded.
The positive electrode is connected to the fuse 41 and the first motor energizing means.
Normally open contact RM of the first motor energizing relay RM1
1a and the electric motor M are grounded in this order.
You. Exciting coil of the first motor energizing relay RM1
One end of RM1b is connected to the fuse 42 and the ignition switch.
Connected to the positive side of battery B via switch IG,
The end is grounded via the motor drive pressure switch SM
I have. That is, the first motor energizing relay RM1 is excited.
The coil RM1b is controlled by the motor driving pressure switch SM.
Is controlled. Also, the ignition switch IG and
A fuse is provided between the connection point A of the fuse 42 and the ground.
43, an alarm generating circuit 44 described later, and an alarm operating means
Series circuit with normally closed contact RKa of relay RK for alarm activation
Is connected, and the exciting coil RKb of the relay RK for alarm activation is connected.
One end of the die has the cathode side on the excitation coil RKb side.
Aether 46, pressure switch SK and fuse for alarm activation
And the other end is grounded.
Have been. That is, the alarm generation circuit 44 operates the alarm activation relay.
-Electricity is controlled by the contact RKa of the RK for alarm activation
The excitation coil RKb of the relay RK is
Is controlled by the switch SK. Also diode
46 is connected to the exciting coil RKb on the cathode side.
50 with the connection point P1 side and a shift lever
(Not shown) is parking range or neutral
ON state when the power is off, and OFF state otherwise
Through the inhibitor switch 52,
Connection switch IG. The alarm generating circuit 44 has a fuse at one end.
43 and the ignition switch IG
B is connected to the other end of the relay RK for activation of the alarm.
Alarm buzzer KB grounded via ILRKb and this
Warning light KL connected in parallel to the NL and the warning light on the anode side
Series circuit of diode 54 on KL side and further warning
Between the connection point P2 between the lamp KL and the diode 54 and the ground
A diode having the connected anode side as a connection point P2 side.
When the brake 56 and the parking brake are activated.
A series circuit of the parking brake switch 58
With the liquid level warning switch 40 connected in parallel with the series circuit
It is configured. The first motor energizing relay R
A second motor energizing means is provided in parallel with the contact RM1a of M1.
Contacts RM2a of all the second motor energizing relays RM2
Connected to excite the second motor energizing relay RM2.
The coil RM2b is connected in parallel with the alarm generation circuit 44
Have been. That is, the alarm generation circuit 44 and the second mode
The excitation coil RM2b of the power supply relay RM2
The energization is controlled by the operating pressure switch SK,
Therefore, the exciting coil R of the second motor energizing relay RM2
M2b is energized by the motor drive pressure switch SM
Excitation coil of the controlled first motor energization relay RM1
The power supply is controlled by a power supply system different from the power supply system RM1b. Further, the first motor energizing relay R
Excitation coil RM1b of M1 and pressure switch for motor drive
Connection point P3 with SM, alarm generation circuit 44, and alarm activation
Between the relay RK and the contact point P4 with the contact RKa,
The diode 60 having the diode side connected to the connection point P3 is inserted.
ing. That is, the alarm operating pressure switch SK is
As described above, the alarm generation circuit 44 and the second motor
To control the energization of the exciting coil RM2b of the relay RM2
Also, the exciting coil R of the first motor energizing relay RM1
M1b is also energized. In other words, the first mode
The excitation coil RM1b of the relay RM1
Pressure switch for alarm actuation in addition to pressure switch for motor drive SM
The energization is also controlled by the switch SK. Next, in the hydraulic booster having the above configuration,
The circuit operation of the control circuit will be described. First, the shift lever
Parking range or neutral range
When the vehicle is stopped while the inhibitor switch 52 is on,
Turn on the ignition switch IG and start the engine.
The hydraulic booster 24 on the inlet port 26 side
Supply pressure (inlet-side supply pressure) is within the normal operating range shown in FIG.
When in the surroundings, the accumulators in accumulators 32 and 34 are normal
Operable range, the motor drive pressure switch SM
Is in the off state by detecting the accumulated pressure of the first accumulator 32
Excitation of the first motor energizing relay RM1
The coil RM1b is not energized and its normally open contact RM1a opens.
Therefore, the electric motor M maintains the stopped state.
The pressure switch SK for alarm operation is connected to the second accumulator.
Since the pressure is detected by detecting the accumulated pressure of
Energizes the excitation coil RKb of the operating relay RK and normally closes it.
Since the contact RKa is open, the alarm generation circuit 44 is not operated.
Keep moving. It should be noted that, as described above, the ignition switch
Immediately after turning on the IG and starting the engine,
Alarm via the inhibitor switch 52 in the ON state
The excitation coil RKb of the relay RK is energized and the normally closed contact R
Ka is opened and the alarm generation circuit 44 is turned off.
, The supply range of the hydraulic booster 24 is normal.
If the pressure is below the second set pressure without being surrounded by, for example,
In this state, the inlet supply pressure is equal to or lower than the second set pressure.
Drives down, drives the electric motor M, and moves up by the pump 2.
Turn off the ignition switch IG while pressing
Accumulators 32 and 34 after stopping
If the accumulated pressure is still below the second set pressure,
The alarm activation pressure switch SK detects this accumulated pressure and turns off.
State and the exciting coil RKb of the relay RK
A non-energized state, the normally closed contact RKa is closed, and an alarm generation circuit 4
4 will not be activated, so prevent malfunction
Can be. During this time, the electric motor M is driven to supply the incoming side.
Since the pressure is immediately increased to the operable range during abnormal conditions,
The operating pressure switch SK is turned on. Next, after the vehicle stops, the hydraulic booster 24 is supplied to the entrance side.
Shift from normal state where the supply pressure is within the normal operation range.
By setting the bar as the drive range, the inhibitor
The switch 52 is turned off, and the vehicle is started to run.
State, and depressing the brake pedal 22 during this time
By performing the operation to operate the hydraulic booster 24,
As a result, the supply pressure on the inlet side decreases, and the first accumulator 3
2, the pressure accumulation is reduced. Then, the storage of the accumulator 32 is performed.
The pressure is the first set pressure of 90 kg / cm^TwoWhen
The motor drive pressure switch SM detects this accumulated pressure and
The first motor energizing relay RM1
Energizing the magnetic coil RM1b to close its contact RM1a,
When the electric motor M is energized and driven,
Therefore, the accumulated pressure is increased, that is, the input side supply of the hydraulic booster 24 is increased.
Increase the supply pressure. Then, the inlet side supply of the hydraulic booster 24
Pressure is 115kg / cm^TwoWhen it is over, the motor drive pressure
Since the switch SM is turned off, the first motor is energized.
The excitation coil RM1b of the relay RM1 becomes in a non-energized state.
Opening the contact RM1a cuts off the power to the electric motor M
Thus, the inlet-side supply pressure maintains a normal operable range. On the other hand, the first motor energizing relay RM1
If there is an abnormality, for example, the first motor energizing relay
If the contact RM1a of RM1 is defective in conduction or the excitation coil
Of the excitation coil RM1b
The current path may be disconnected, the fuse 42 may be blown,
If the pressure switch for data actuation SM is damaged,
Is the supply pressure on the inlet side of the hydraulic booster 24, that is, the first accumulator.
Even if the accumulated pressure of the mulrator 32 becomes lower than the first set pressure, the first
Motor relay RM1 is inactive
Since the electric motor M is not energized as in
Each time is performed, the inlet side supply pressure decreases. In such a case
Means that the accumulated pressure of the first accumulator 32 is completely discharged.
As a result, the accumulated pressure of the second accumulator 34 decreases. this
The accumulator pressure of the second accumulator 34 is used as a pressure switch for alarm activation.
Switch SK, the accumulator 34 accumulates
65 kg / cm which is the second set pressure^TwoWarning when
The operating pressure switch SK is turned off and the alarm is activated.
When the exciting coil RKb of the relay RK is de-energized,
The normally closed contact RKa is closed and the alarm generation circuit 44 and the
2 motor excitation relay RM2 excitation coil RM2b
Since the power is supplied, the alarm buzzer KB sounds and the warning light KL
Lights up, the second normally open contact RM2a is closed, and the electric motor
Motor M is energized and driven to supply the hydraulic booster 24 on the inlet side.
The pressure is increased. And the inlet side supply pressure is 80 kg / cm^Two
Then, the alarm pressure switch SK is turned on.
To energize the excitation coil RKb of the alarm activation relay RK
The contact RKa is opened to open the alarm generation circuit 44 and the second mode.
The energizing coil RM2b of the relay RM2 is turned off.
The warning buzzer KB stops and the warning light KL
The light turns off and the second contact RM2a is opened to open the electric motor.
The drive of the motor M is stopped and the supply pressure on the inlet side of the hydraulic booster 24 is abnormal.
When the operable range is maintained. And like this,
Operating pressure switch SK has hysteresis characteristics
From the fact that the accumulator 34 is provided,
Immediately generates an alarm even when the vehicle is in a running state and a braking operation is performed
Circuit 44 does not operate. Further, a first motor energizing relay RM1
Is normal and the motor drive pressure switch SM is broken.
In addition to this, the second motor energizing relay RM2 is different.
If there is always, for example, the second motor energizing relay RM2
Of the excitation path of the excitation coil RM2b
The excitation coil RM2b is burned out or the contact RM2a is
If the continuity is poor, the hydraulic boot
The supply pressure on the inlet side of the star 24 is reduced to 65 k of the second set pressure.
g / cm^TwoWhen it becomes the following, 80kg / cm^Twothat's all
The operation state of the alarm generation circuit 44 when
Same as, but the second motor energizing relay RM2 is activated
Therefore, the electric motor M is connected to the first motor energizing relay R
The energization is controlled only by opening and closing the contact RM1a of M1.
The operable range at the time of the abnormality of the input side supply pressure is maintained. The vehicle is stopped and the parking brake
When the switch 58 is turned on, the warning light KL lights up, and then
When the ignition switch IG is turned off, the warning light KL
Disappear. This warning light KL turns off the buzzer in the reservoir tank 8.
Liquid level warning switch 4 even when the amount of rake liquid is insufficient
0 turns on and lights up, but the ignition switch
When the IG is turned off, the warning light KL naturally goes out. As described above, in the present embodiment, the second motor
The exciting coil RM2b of the power relay RM2 is the first motor
The power supply system of the exciting coil RM1b of the energizing relay RM1
Are connected to different power systems,
Even if an abnormality occurs in the power relay RM1, the second motor is energized.
Relay RM2 operates to energize the electric motor M,
The operable range when the supply pressure on the inlet side of the hydraulic booster 24 is abnormal is
Maintained to prevent abnormal lowering. The first motor energizing relay RM1
Excitation coil RM1 is only motor drive pressure switch SM
Control by alarm pressure switch SK
The pressure switch SM for motor drive is broken
Or the second motor energizing relay RM2 is not operating
At the time of operation of the first motor energizing relay RM1.
The electric motor M is energized to prevent the supply pressure from dropping abnormally.
Is stopped. Further, the supply pressure on the inlet side of the hydraulic booster 24 is
1st motor energization at normal time within normal operating range
Of the hydraulic booster 24 by the operation of the relay RM1
The supply pressure is controlled to prevent an abnormal decrease in the inlet supply pressure.
When the inlet side supply pressure becomes lower than the second set pressure.
Since the second motor energizing relay RM2 operates,
Of the second motor energizing relay RM2
The second motor energizing relay RM2 is a low-life, inexpensive
Can be configured with a relay. Further, a motor driving pressure switch SM is provided.
The pressure switch for alarm activation SK has hysteresis characteristics
In the case of not having hysteresis characteristics
As described above, the supply pressure on the inlet side of the hydraulic booster 24 is reduced to the first or second pressure.
Frequently increasing or decreasing the set pressure
The switching phenomenon disappears and the switches SM and SK are frequently
The on / off operation is not repeated. In the above embodiment, the first and second modes are used.
First and second motor energizing relays as motor energizing means
Apply RM1 and RM2, and as an alarm activation means
Although the relay RK for alarm activation was applied,
Photocouplers can be applied, as well as bipolar tigers.
Switching elements such as transistors and field effect transistors
Where switching elements are used.
The motor drive to the control circuit that controls the base current etc.
Operating pressure switch SM and alarm operating pressure switch SK
May be inserted. The motor driving pressure switch SM and the alarm
The on / off operation of the pressure switch SK for
First motor energizing relay RM1 and alarm activation relay
When the RK excitation coils RM1b and RKb are not energized,
The state of the open / closed state of the contact RM1a and the contact RKa
When the supply pressure on the inlet side of the hydraulic booster 24 becomes equal to or less than the first set pressure.
Pump 2 so that the supply pressure on the inlet side is increased by the pump 2.
Energize the dynamic motor M and reduce the inlet pressure to below the second set pressure.
When the power is turned on, the electric motor M is energized and an alarm
It is only necessary that 44 be energized. For example, the first contact
Using the point RM1a as a normally closed contact, the motor driving pressure switch
H is the first set pressure when the supply pressure on the inlet side of the hydraulic booster 24 is the first set pressure.
If it becomes less than the above, it will be off and above the normal operation range
It may be set to the on state when it exceeds the near limit value.
Also, the contact RK of the relay RK for alarm activation is normally open.
The pressure switch SK for alarm operation is set to the input side supply pressure
Becomes ON when the pressure falls below the second set pressure
Turns off when the value exceeds the upper limit of the operable range
You may do so. Further, in the above embodiment, the second motor
An alarm generation circuit for the excitation coil RM2b of the power relay RM2
44, but this exciting coil RM2b is
It is energized by the contact RKa of the relay RK
For example, the excitation coil RM2b issues an alarm
Connects to the input side of the raw circuit 44 and the output side of the alarm generation circuit 44.
Between the point RKa, the output side of the contact RKa, and the fuse 4
8 and the diode 60, or between the diode 60 and the connection point P4.
It may be connected between them. Further, in the above embodiment, the hydraulic booster 2
Between two pumps 2 and 4 and two accumulators 32 and 34
Is provided, but only one accumulator may be provided. this
In some cases, the motor is driven at the connection point between the accumulator and the piping.
Pressure switch SM and alarm pressure switch SK
Is provided, which simplifies the overall device configuration.
It is. Further, the pressure switch has a hysteresis characteristic.
Pressure switch SM for driving motor and alarm
Although two pressure switches SK are provided, the hysteresis characteristics
Four pressure switches that do not have
The set pressure of the switch to the normal supply pressure on the inlet side of the hydraulic booster 24.
Values near the upper limit of the operable range during abnormal operation and the operable range during abnormal operation
May be set to values close to the respective lower limits. Further, the motor driving pressure switch SM or
Indicates that only one of the pressure switches SK
It may have a steeresis characteristic,
Make sure that switches SM and SK do not have hysteresis characteristics
It may be. Further, in the above embodiment, the pressure detecting means
Applied two pressure switches SM and SK as
Uses a pressure sensor that outputs a detection signal according to the detected pressure
Then, the detection signal of this pressure sensor is, for example, set to a first setting.
And a reference value corresponding to the second set pressure are set.
Input to at least two comparators and output
The energization of the relays RM1 and RM2 may be controlled.
No. In this case, use four comparators
Hysteresis characteristics can be obtained,
By changing the reference voltage input to the
By changing the width W of the
The degree can be set arbitrarily according to the driver's preference.
You. Further, the motor driving pressure switch SM and
And normal operation, which is the set pressure of the pressure switch SK for alarm activation
Values near the upper limit of the operable range and
The values near the lower limit (the first and second set pressures) are listed in the above embodiment.
Value is not limited to the first and second
The values of the filling pressure of the accumulators 32 and 34 are also the values of the above embodiment.
It is not limited to. Further, in the above embodiment, the second motor
Excitation coil RM2b of power relay RM2 and for alarm activation
Connect the contact RKa of the relay RK to the ignition switch IG
Has been described in connection with battery B via
Not limited to this, other batteries may be provided and connected to this
You may do it. In this case, the motor drive pressure switch
Switch SM and alarm activation pressure switch SK
Excitation coil of the controlled first motor energization relay RM1
Power supply to the power supply RM1b and the relay RK for alarm activation.
Second excitation coil R controlled to be energized by contact RKa
Since the power supply to M2b is completely different, oil
An abnormal decrease in the supply pressure on the inlet side of the pressure booster 24 can be prevented. Further, in the above embodiment, the fluid pressure booster
Although the hydraulic booster 24 was applied as the
It can also be applied to pressure boosters. [0047] [0048] [0049] [0050]【The invention's effect】 As explained above, Claim1Hydraulic
According to the control circuit in the booster,First pressure switch
The supply pressure to the hydraulic booster falls below the first set pressure.
Control of the excitation coil of the first relay
This controls the opening and closing of the contacts of the first relay
The energization of the electric motor is controlled and the second pressure switch is controlled.
Switch detects that the supply pressure has fallen below the second set pressure.
And the exciting coil of the second relay is connected to the first relay.
Since energization is controlled by a power supply system different from the excitation coil,one
Power supplysystemEven if an error occurs, the other power supplysystemBy
Supply to the fluid pressure booster
Abnormal drop in supply pressureToIt can be prevented more reliably. [0051]Moreover,The first pressure switch breaks and
When an abnormality occurs in the second relay, the fluid pressure booster
When the supply pressure becomes equal to or lower than the second set pressure, the second pressure switch
Switch controls the energization of the first relay to the electric motor.
Since the power is supplied and the pump is driven to increase the supply pressure,
Abnormal drop in supply pressure regardless of circuit abnormality as described above
Is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a hydraulic circuit showing one embodiment of the present invention. FIG. 2 is a circuit configuration diagram of the embodiment. FIG. 3 is a graph illustrating the operation of the embodiment. FIG. 4 is a control circuit diagram in a conventional hydraulic booster. [Description of Signs] M Electric motor SM Motor driving pressure switch (pressure detecting means) SK Alarm operating pressure switch (pressure detecting means) RK Alarm operating relay (alarm operating means) RM1 First (motor energizing) relay (First motor energizing means) RM2 Second (motor energizing) relay (second motor energizing means) RM1a Contact point of first (motor energizing) relay RM2a Contact point of second (motor energizing) relay RKa Contact point RM1b of alarm activation relay RM1b Excitation coil RM2b of first (motor energization) relay Excitation coil RKb of second (motor energization) relay excitation coil KB of alarm activation relay Alarm buzzer KL Warning light 2 Pump 24 Hydraulic booster (fluid pressure booster) 32 First accumulator 34 Second accumulator 44 Alarm generation circuit

Claims (1)

(57) In the hydraulic booster which is adapted to supply the Patent Claims 1. A fluid pressure constant pressure of the working fluid away from pump driven by an electric motor to the booster, current path of the electric motor Contact
First and second relays interposed in parallel, and the fluid
The supply pressure to the pressure booster has fallen below the first set pressure
Pressure switch for detecting pressure, and the fluid pressure booster
Supply pressure to the second set pressure lower than the first set pressure
The second pressure switch that detects
And the exciting coil of the first relay is the first relay.
Energized by the pressure switch and the second pressure switch
And the exciting coil of the second relay is driven by the second voltage.
A power switch different from the first exciting coil
A control circuit in a hydraulic booster, wherein the power supply is controlled by a power system.