JPS63103755A - Antilock brake device - Google Patents

Abstract

PURPOSE:To realize the safe brake application by suppressing the supply of the pressurized liquid into a wheel master cylinder from an accumulator when the hydraulic pressure of the pressurized liquid which is supplied from the accumulator is higher than a brake hydraulic pressure such as in the case when the stepping-in force of a pedal is reduced during the antilock operation. CONSTITUTION:An always opened solenoid valve 11 is connected to the cylinder chamber 4 of each regulator valve connected with the hydraulic pressure output parts 1a and 1b of a master cylinder 1, and a wheel brake 14 for rear wheels is connected with the solenoid valve 11 through a hydraulic control valve 12. The hydraulic control valve 12 is connected to a reservoir 16 through an always closed solenoid valve 15, and a pump 22 is connected with the reservoir 16, and an accumulator 25 is connected on the discharge side, and further connected to the valve chamber 6 of the above-described valve 3 through an always opened solenoid valve 26. The regulator valve 3 suppresses the supply of the hydraulic pressure supplied from the accumulator 25 into a brake device when the pressure in the valve chamber 6 is higher than the pressure in the cylinder chamber 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-lock brake device that prevents wheels from locking and sliding on the road surface due to excessive brake fluid pressure and safely stopping a vehicle. .

``Prior Art'' As an anti-lock brake device for use in automobiles, the one shown in Utility Model Application No. 60-50750 has been proposed as an example. This device includes a lock detection section that detects wheel locking, a hydraulic pressure modulation section that lowers brake fluid pressure in response to detection by the lock detection section, and a pump that increases the brake pressure that has decreased again to prevent wheel locking. It is provided in the middle of the path that transmits the hydraulic pressure generated in the master cylinder operated by the brake pedal to the brakes of each wheel.

Then, when the vehicle is braking, just before the wheels lock, the brake fluid pressure is lowered to avoid the wheels locking, and when the wheel rotational speed has recovered, the brake fluid pressure is increased again to apply the brakes. The high pressure hydraulic pressure generated by the pump is used to increase this brake fluid pressure.

In this type of anti-lock brake system, a 3-boat switching solenoid valve is interposed in the brake fluid passage between the brake, the master cylinder, and the pump, and the current applied to the solenoid of this valve is controlled to control the brake fluid flow. Three modes were realized: pressure increase, pressure decrease, and pressure increase and decrease pressure maintenance.

``Problems to be Solved by the Invention'' However, although electrical failure countermeasures are taken in the anti-lock brake system as described above, in the unlikely event that a mechanical failure occurs, such as when the pump malfunctions while the anti-lock is in operation. If the system stopped working, it was impossible to take immediate action. Therefore, solenoid valves require precision, require high reliability along with motors and pumps, and have the disadvantage of high cost.In particular, the current value required to take three modes: pressure increase, pressure decrease, and pressure increase and decrease pressure maintenance. To control the solenoid valve, a backup mechanism is required.
In this respect as well, the cost was high.

Additionally, there was a risk that pressurized fluid from the pump would be directly introduced into the brake due to a timing shift in the operation of the solenoid.

An object of the present invention is to provide an anti-lock brake device that solves the above problems.

"Means for Solving the Problems" The present invention has the following configuration in order to achieve the above object. That is, a sensor that detects the rotational state of the wheel, a controller that issues a solenoid activation signal to the actuator based on the signal from this sensor, the actuator that increases or decreases the brake fluid pressure based on the activation signal of this controller, and a sensor that is driven by an electric motor. In the anti-lock brake device, the actuator includes a first solenoid valve that opens and closes a brake fluid passage between the master cylinder and the brake. , a second solenoid valve that opens and closes a brake fluid passage for returning brake fluid from the brake to the master cylinder; a third solenoid valve that opens and closes a brake passage between the brake fluid and the brake; and the first solenoid valve that opens and closes the brake fluid passage between the brake fluid and the brake. The brake fluid passage is interposed between the solenoid valve and the master cylinder, and has a piston in the cylinder. Brake fluid pressure from the master cylinder is introduced into a chamber at one end of the piston in the cylinder, and into a chamber at the other end. Pressure fluid from the accumulator is introduced, and when the pressure of the pressure fluid from the accumulator is higher than the brake fluid pressure from the master cylinder, the pressure fluid from the accumulator is prevented from being supplied to the brake. The regulator valve includes a ball valve.

"Operation" When the hydraulic pressure of the hydraulic fluid from the Akinimulator that supplies the brakes is higher than the brake hydraulic pressure from the master cylinder, such as when the depression force on the brake pedal is reduced during anti-lock operation, the regulator valve and solenoid The action of the valve prevents pressurized fluid from the accumulator from being supplied to the wheel cylinder.

“Embodiment” An embodiment of the present invention will be described below based on the drawings. The drawing shows an example of two-system control of the anti-lock brake system, in which 1 is the brake pedal 2 installed on the vehicle body.
This is a master cylinder connected to a hydraulic output section 1a of this master cylinder 1.

Regulator valve 3.3 is attached to each lb by piping.
is connected.

The regulator valve 3 includes a piston 5 slidably provided in a cylinder chamber 4 formed in a cylinder, and a valve chamber 6 provided in the piston 5 in the axial direction of the piston 5.
The inner ball valve 7 is connected via a rod, the piston 5 is urged toward the valve chamber 6 by a spring 8 provided in the cylinder chamber 4, and the ball valve 7 is urged toward the valve chamber 6 by a spring 8 provided in the cylinder chamber 6. When the oil pressure in the valve chamber 6 becomes higher than the oil pressure in the cylinder chamber 4, the ball valve 7 moves toward the cylinder chamber 4 against the force of the spring 8, and the valve It is designed to sit on a valve seat lO provided on the chamber wall.

A normally open first solenoid valve (2-boat 2-position switching solenoid valve) (actuator > lj) which is normally open is connected to the cylinder chamber 8 via piping, and this first solenoid valve 11 is connected to the rear wheel brake via piping. A wheel cylinder (brake cylinder) 14 of a rear wheel 13 is connected as shown in the drawing through a hydraulic pressure control valve (P valve) 12 which is an input control device.

The hydraulic control valve 12 is connected to the reservoir 16 of the master cylinder l via a second solenoid valve (two-boat, two-position switching solenoid valve) (actuator) 15 which is normally closed.

Further, a wheel cylinder (brake cylinder) 19 of a front wheel 18 is connected to the valve chamber 6 via a check valve 17 on the side of the cylinder chamber 4 from the valve seat 10 of the regulator valve 3 through piping. The check valve 17 is configured to allow fluid to flow from the regulator valve 3 to the wheel cylinder 19, but not to flow in the opposite direction.

Further, the hydraulic output parts 1a and 1b of the master cylinder 1 are each connected to a connecting part between the hydraulic pressure control valve 12 and the second solenoid valve 15 via a check valve 20 by piping. This check valve 20 is designed to allow fluid to flow from the P valve 12 to the master cylinder l, but not to flow in the opposite direction.

On the other hand, master cylinder 1 glue reservoir! 6 is connected to a pump 22 via a check valve 21 by piping. This pump 22 is driven by an electric motor 23.

The pump 22 is connected to an akinimulator 2 via a check valve 24.
5 is connected. A third solenoid valve (2-boat 2-position switching solenoid valve) (actuator) 26 which is normally open is connected to the stiffness regulator 25 by piping, and this third solenoid valve 26 is connected to the regulator pulp 3 by piping. The inner ball valve 7 is communicated with the valve chamber 6 on the side opposite to the piston 5. The check valve 21 is a valve that allows fluid to flow from the reservoir 16 to the pump 22, but does not allow fluid to flow in the opposite direction.
This is a valve that allows fluid to flow in the direction from the accumulator 25, but does not allow fluid to flow in the opposite direction.

On the other hand, a wheel rotation speed sensor 27 is provided on the side of the wheel to detect the rotation state of the wheel. Second. Third solenoid valve 11.15
．． A controller (not shown) is connected to 26 to issue a solenoid activation signal. When this controller enters the anti-lock state described later, the first . Second. Turn the third solenoid valve 11, 15.26 to 0N-O as shown below.
It is designed to cause FF.

Brake fluid pressure mode Hold Reduce pressure hold Pressure increase 1st solenoid valve ON ON ON ON 2nd solenoid valve OFF ON OFF
OFF 3rd solenoid valve OFF OFF
OFF ON Next, the operation of the anti-lock brake device configured as described above will be explained.

The drawing shows a normal braking state when the brake pedal is depressed. In the state shown in this drawing, the motor 23
operates, the pump 22 supplies brake fluid from the reservoir 16 to the accumulator 25, and the check valve 21. pump 22
．． It is stored through the check valve 24.

At the same time, brake fluid flows from the master cylinder 1 through the piping into the cylinder chambers 4 of both regulator valves 3, passes through the first solenoid valve 11, flows into the wheel cylinder 19 of the front wheel 18, and operates the front wheel 18. At the same time, the hydraulic pressure flows into the wheel cylinder 14 of the rear wheel 13 via the hydraulic pressure control valve 12 and brakes the rear wheel 13.

In this case, when the brake fluid pressure in the wheel cylinder 14.19 increases, a braking force to stop the rotation of the wheel is generated in the wheel cylinder 14.19 and increases, causing the tire and road surface of the wheel to increase. J! ?
! When the braking force becomes greater than the force that attempts to rotate the wheel due to frictional force, the wheel rotation rapidly decelerates and enters an anti-lock state. At this time, if the rate of change in the wheel rotational speed, that is, the deceleration, exceeds a predetermined value, the wheel rotational speed sensor 2
Based on the detection signal of 7, the controller determines that this is a sign that a wheel lock will occur, and immediately operates the first solenoid valve 11 to close it, and sets the brake fluid pressure to a holding mode (the first solenoid valve 11 is ON, The second solenoid valve 15 is OFF.

The third solenoid valve 26 is in an OFF state. )
shall be.

As a result, master cylinder 1 and wheel cylinder 14
．． 19 and the wheel cylinder 14.
Stop the rise in brake fluid pressure in 19.

After a predetermined period of time, the controller operates the second solenoid valve 15 to open it, and the brake fluid pressure is set to a pressure reduction mode (the first solenoid valve 11 is turned on, the second solenoid valve 15 is turned on, and the third solenoid valve is turned on. 26 is in the OFF state). As a result, the brake fluid in the wheel cylinder 14.19 returns to the reservoir 16, and the brake fluid pressure in the wheel cylinder 14.19 is reduced.

Therefore, the rotation speeds of the front wheel 1B and the rear wheel 13 start to increase.

After a predetermined period of time, the controller closes the second solenoid valve 15 and maintains the brake fluid pressure (the ml solenoid valve 11 is ON, the second solenoid valve t5 is OFF, and the third solenoid valve 26 is OFF). ). This maintains the current pressure reduction mode. Therefore, the rotational speed of the wheels increases.

After a predetermined period of time, the controller opens the third solenoid valve 26 and sets the brake fluid pressure to the pressure increase mode (the first solenoid valve 11 is ON, the second solenoid valve 15 is OFF, and the third solenoid valve 26 is ) is in the ON state.

As a result, pressure oil from the accumulator 25 passes through the third solenoid valve 26, flows into the valve chamber 6 of the regulator valve 3, and further passes through the check valve 17°P valve 12 and flows into the wheel cylinders 14 and 19, and flows into the wheel cylinders 14 and 19. Increase the brake fluid pressure in cylinder 14.19.

As a result, the hydraulic pressure in the valve chamber 6 gradually increases, and when the hydraulic pressure of the hydraulic fluid from the accumulator 25 becomes higher than the brake hydraulic pressure from the master cylinder l, the brake fluid in the valve chamber 6 moves the ball valve 7 into the cylinder. The piston 4 is moved toward the chamber 4 side, and the piston 4 is also moved in the same direction as the movement direction of the ball valve 7, so that the ball valve 7 is seated on the valve seat lO.

Therefore, from the accumulator 25 to the wheel cylinder 1
4. Stop the supply of brake fluid to 19, thereby maintaining the pressure increase mode.

After a predetermined period of time, the controller turns off the third solenoid valve 26 to return to the initial state of the anti-lock state. From then on, repeat each of the above modes until the front wheel 1
8. The rear wheel 13 is braked to stop the vehicle.

By the way, when the depression force on the brake pedal 2 is relaxed during anti-lock operation, the brake fluid pressure in the valve chamber 6 becomes higher than the brake fluid pressure in the cylinder chamber 4, and the brake fluid pressure in the valve chamber 6 is increased by the ball valve 7. is moved toward the cylinder chamber 4 side, and the piston 4 is also moved in the same direction as the moving direction of the ball valve 7, so that the ball valve 7 is seated on the valve seat 10.

Therefore, from the accumulator 25 to the wheel cylinder 1
4. Cut off the brake fluid supply to 19. That is, it prevents a hydraulic pressure higher than the brake hydraulic pressure generated in the master cylinder l from being supplied to the wheel cylinders 14 and 19.

As described above, according to this embodiment, it is possible to prevent the hydraulic pressure from being applied to the wheel cylinders 14.19 in excess of the hydraulic pressure intended by the driver, and to prevent the front wheel 18. To prevent rear wheel 13 from locking.

"Effects of the Invention" According to the present invention, a sensor that detects the rotational state of a wheel;
A controller that issues a solenoid activation signal to an actuator based on a signal from this sensor, the actuator that increases or decreases brake fluid pressure based on the activation signal of this controller, a pump driven by an electric motor, and a pressurized fluid discharged from the pump. In the anti-lock brake device, the actuator includes a first solenoid valve that opens and closes a brake fluid passage between the master cylinder and the brake, and a brake fluid passage that returns brake fluid from the brake to the master cylinder. A second solenoid valve that opens and closes a passage, a third solenoid valve that opens and closes a brake passage between the accumulator and the brake, and a brake fluid passage that is interposed between the first solenoid valve and the master cylinder. The brake fluid pressure from the master cylinder is introduced into one end of the piston in the cylinder, and the pressure fluid from the accumulator is introduced into the other end. When the hydraulic pressure of the pressurized liquid is higher than the brake hydraulic pressure from the master cylinder, the regulator valve has a ball valve that prevents the pressurized liquid from the accumulator from being supplied to the brake. This eliminates the need for a pressure boosting pump for the anti-lock brake system, greatly reducing mechanical failures such as those that would occur if the pressure boosting pump were to fail during anti-lock operation, simplifying construction, and ensuring special precision of the components. This eliminates the need for ordinary 2-vote 2
A position switching solenoid valve can be used,
This eliminates the need to control the solenoid valve with the current value, eliminates the need for a backup mechanism, and reduces costs. In addition, since a holding mode can always be provided between the pressure reduction mode and the pressure increase mode, it is possible to prevent pressure fluid from the pump from being introduced directly to the brake due to a shift in the timing of the solenoid valve operation, and also prevent the driver It is safe because it prevents applying more hydraulic pressure to the brake than the intended hydraulic pressure.

[Brief explanation of the drawing]

The drawing is a hydraulic circuit diagram showing an embodiment of the present invention. ! ......Master cylinder, 3...
...Regulator valve, 7...Ball valve, 11...First solenoid valve (2-boat 2-position switching solenoid valve) (actuator), 14.19・・・・・・・・・Wheel cylinder (brake cylinder), 15・・・・・・・・・
・Second solenoid valve (2-boat 2-position switching solenoid valve) (actuator), 22...
... Pump, 23 ...... Electric motor, 2
5...Accumulator, 26...
...Third solenoid valve (2-boat 2-position switching solenoid valve) (actuator), 27...
...Wheel rotation speed sensor.

Claims (2)

[Claims] (1) a sensor that detects the rotational state of the wheels; a controller that issues a solenoid activation signal to the actuator based on a signal from the sensor; and the actuator that increases or decreases brake fluid pressure based on the activation signal of the controller;
In an anti-lock brake device that includes a pump driven by an electric motor and an accumulator that stores pressurized fluid discharged from the pump, the actuator is a first actuator that opens and closes a brake fluid passage between a master cylinder and the brake. a solenoid valve; a second solenoid valve that opens and closes a brake fluid passage for returning brake fluid from the brake to the master cylinder; a third solenoid valve that opens and closes a brake passage between the accumulator and the brake; It is interposed in a brake fluid passage between the solenoid valve No. 1 and the master cylinder, has a piston in the cylinder, and brake fluid pressure from the master cylinder is introduced into a chamber on one end of the piston in the cylinder, and a chamber on the other end side. Pressure fluid from an accumulator is introduced into the brake, and when the pressure of the pressure fluid from the accumulator is higher than the brake fluid pressure from the master cylinder, a ball prevents the pressure fluid from the accumulator from being supplied to the brake. An anti-lock brake device comprising: a regulator valve having a valve; (2) While the brake fluid pressure supplied to the brake is switched from an increased pressure state to a reduced pressure state or from a reduced pressure state to an increased pressure state by the operation of the actuator,
The anti-lock brake device according to claim 1, further comprising a holding mode in which the pressure before being switched in this way is maintained.