JPS62255265A - Antilock braking device - Google Patents

Abstract

PURPOSE:To dispense with a booster pump, simplify a device in structure and make it inexpensive, by interposing an actuator between an on-off valve in a brake passage and a wheel cylinder, and installing plural regulator valves to be opened by a command out of a controller and a variable displacement chamber having the specified spring pressure connected to each of these valves. CONSTITUTION:An actuator 28 is interposed between an on-off valve 4, opening or closing a brake fluid passage 3 between a master cylinder 1 and a wheel cylinder 6, and this wheel cylinder 6. And, there are provided with plural regulator valves 13, 20, 21 and 22 being normally closed out opened by a command out of a controller 12, and a variable displacement chamber 24 having the specified spring pressure to be connected to each of these valves. Therefore, a booster pump becomes useless, and a device structure is simplifiable, thus an antilock braking device is securable in an inexpensive manner. In addition, with omission of a pump, a part of engine output or power consumption in a battery comes to nothing, thereby making it economizable.

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 this lock detection section, and a fluid pressure modulation section that increases the reduced brake pressure again to prevent wheel locking. The pump part is provided in the middle of a 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. This pump is connected to an axle via a pulley and a belt, and is driven via the pulley and belt by rotation of the axle.

In addition, there are other anti-lock brake devices of the same type that use part of the engine's output or battery power as the drive source for the pump.

``Problems to be Solved by the Invention'' However, in the above-mentioned anti-lock brake device, a pump is required to repressurize the brake fluid pressure, which makes the device complicated, and furthermore, it is difficult to drive this pump. However, because it uses part of the engine's output or battery power, it consumes a lot of energy and is uneconomical.

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

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration. That is, a sensor that detects the rotational speed of the wheel, a controller that calculates the rotational speed of the wheel and the rate of change of the rotational speed of the wheel from the signal of this sensor, and issues a brake force adjustment command from the results, and a command of this controller. In the anti-lock brake device, the actuator includes an on-off valve that opens and closes a brake fluid passage between a master cylinder and a wheel cylinder, and an on-off valve that opens and closes a brake fluid passage between a master cylinder and a wheel cylinder; The controller includes a plurality of regulating valves which are normally closed and are opened in response to a command from the controller, and a plurality of variable volume chambers each having a predetermined spring pressure and respectively connected to the plurality of regulating valves.

"Operation" High brake fluid pressure for operating the brakes is stored in a predetermined variable volume chamber, and when the wheels are about to lock during braking, a predetermined regulating valve is opened by the action of the controller, and a predetermined regulating valve is stored in a predetermined variable volume chamber different from the variable volume chamber. The on-off valve is stored in the variable volume chamber of the brake fluid between the wheel cylinders to reduce the brake fluid pressure, thereby avoiding wheel locking, and when the wheel rotation speed is restored, the predetermined variable volume chamber is installed in the brake fluid piping. Return the brake fluid in the volume chamber and increase the brake fluid pressure again.
Brakes are applied by moderate friction between the wheels and the road surface.

"Embodiment" Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 4.

Reference numeral 1 in FIG. 1 is a master cylinder connected to a brake pedal 2 provided on the vehicle body, and this master cylinder I includes a pipe 31, an on-off valve (electromagnetic valve) which is normally open, 4. Piping 5
The brake wheel cylinder 6 is also connected through this.

The on-off valve 4 includes a bypass passage 8 having a check valve 7 that allows fluid to flow from the wheel cylinder 6 to the master cylinder l, but does not allow fluid to flow in the opposite direction.
is connected.

On the other hand, a wheel rotation speed sensor 9 is provided on the side of the wheel to detect the rotation speed of the wheel. Further, a pedal sensor lO is provided near the brake pedal 2 to detect the position of the brake pedal 2. This pedal sensor IO has a signal line IIa, a controller 12. The wheel rotation speed sensor 9 is also connected via the signal line 11b.

A pressure increasing cylinder (pressure increasing variable volume chamber) 14 is connected to the piping 5 via a normally closed regulating valve (electromagnetic valve) 13 . Regulating valve 13. The piping between the pressure increasing cylinders 14 and the piping 5 are provided with a bypass having a check valve 15 that allows fluid to flow from the piping 5 toward the pressure increasing cylinder I4, but prevents fluid from flowing in the opposite direction. Passage 1
6 is connected.

In addition, the piping 5 is connected to a pressure reducing cylinder (variable volume chamber opening 7 for pressure reduction) having a large spring force (variable volume chamber opening 8 for pressure reduction) having a large spring force. cylinders (variable volume chambers for pressure reduction) 19 are connected by piping via normally closed regulating valves (electromagnetic valves) 20, 21, and 22, respectively.

Open/close valve 4. Each regulating valve 13, 20, 21, 22 is connected to the controller 12 via a signal line 23, and the controller I2 has a built-in microcomputer and calculates the rotational speed of the wheels and the rate of change in the rotational speed of the wheels. ,
Determine whether the brake force is excessive or insufficient and open/close the valve 4. Each regulating valve 13.
20, 21, and 22 are operated via a signal line 23.

Pressure increase cylinder 14. Decompression cylinder 17.18°19
All have the same configuration: a cylinder 24, a piston 25 slidably provided in the cylinder 24, a spring 26 provided at the bottom of the cylinder 24, a spring 26 provided between the pistons 25, an earthen wall of the cylinder 24, and a piston 25. It consists of a variable volume chamber 27 provided between 25 and 25.

In addition, piping 3, 5. Open/close valve 4. Adjustment valve 13, 20°2+
, 22 pressure increasing cylinder 14. Decompression cylinder 17.18
．． +9. An actuator 28 is constituted by the bypass passages 8, 16, the check valve 7.15, and the like.

Next, the operation of the anti-lock brake device configured as described above will be explained.

When the brake pedal 2 is depressed, brake fluid flows from the master cylinder l to the pipe 3. Open/close valve 4. It flows through the pipe 5 to the wheel cylinder 6, increasing the internal pressure of the wheel cylinder 6. At the same time, the brake fluid is released from the open/close valve 4. Bypass passage +
6. It passes through the check valve 15 and flows into the variable volume chamber 27 of the pressure increasing cylinder [4] by pushing down the piston 25 against the force of the spring 26.

At this time, the pedal sensor lO detects that braking has started, and the controller 12 is activated.

When the brake fluid pressure in the wheel cylinder 6 increases, a braking force is generated and increased in the wheel cylinder 6 to try to stop the rotation of the wheel, and the friction force between the wheel tire and the road surface causes the wheel to rotate. If the braking force becomes greater than the force that is trying to stop the wheel, the rotation of the wheel will suddenly decelerate. If the rate of change in the rotational speed of the wheels at this time, that is, the deceleration, exceeds a predetermined value, the controller 12 determines that this is a sign that a wheel lock will occur, and immediately operates the on-off valve 4 to close it. Cylinder I and wheel cylinder 6
The passage (piping 3.5) between the wheel cylinder and the brake fluid pressure in the wheel cylinder 6 is stopped from increasing. Then, the brake fluid pressure at this time is the wheel cylinder 6. It is enclosed within the piping 5 and the pressure increase cylinder 14.

After this, if the rotation of the wheel continues to decelerate, the controller I2 determines that the brake fluid pressure is too high and operates the regulating valve 20 to open it, and the brake fluid pressure is sealed in the wheel cylinder 6 and piping 5. Cylinder 1 for reducing brake fluid pressure
7 into the variable volume chamber 27 by pushing down the piston 25 against the force of the spring 26. As a result, the brake fluid pressure in the wheel cylinder 6 and pipe 5 decreases.

After this, if the brake fluid pressure is still too high, controller 1
2, the controller 12 operates the regulating valve 20 to close it and operates the regulating valve 21 to open it. As a result, the brake fluid sealed in the wheel cylinder 6 and the piping 5 flows into the variable volume chamber 27 of the depressurizing cylinder 18 by pushing down the piston 25 against the force of the spring 26, thereby causing the brake fluid to flow into the wheel cylinder 6 and the piping 5. 6. The brake fluid pressure in the pipe 5 further decreases.

In this way, when the controller 12 determines that the brake fluid pressure in the wheel cylinder 6 is too high, the controller 12 sequentially opens and closes the regulating valves 20, 21, and 22, and sequentially moves the spring force from the pressure reducing cylinder with a strong spring force to the pressure reducing cylinder. Brake fluid is introduced into the pressure reducing cylinder where the force is weak.

Among the pressure reduction cylinders, the pressure reduction cylinder with the weakest spring force is the pressure reduction cylinder 19 in this embodiment,
The springs of this pressure reducing cylinder 19 are set such that the brake fluid pressure is lower than the brake fluid pressure that generates the braking force that just locks the wheels when the frictional force between the wheels and the road surface is the lowest when the vehicle is running. Set the power.

Therefore, when the controller 12 determines that the brake fluid pressure in the wheel cylinder 6 is too high as described above, the controller 12 sequentially opens and closes the regulating valves 20, 21, and 22, and sequentially applies a strong spring force. As the brake fluid is repeatedly introduced from the pressure reduction cylinder to the pressure reduction cylinder with a weaker spring force, the rotational speed of the wheels begins to increase.

When the rotational speed of the wheel becomes higher than a predetermined value, the controller 12 determines that the braking force is insufficient, and closes all of the regulating valves 20, 21, and 22 in order to increase the brake fluid pressure in the wheel cylinder 6. Then, brake fluid is sealed in the pressure reducing cylinders 17, 18, and 19, and the regulating valve I3 is opened to pump the brake fluid in the pressure increasing cylinder i, which is higher than the brake fluid pressure in the wheel cylinder 6 at that time, to the pipe 5. The brake fluid pressure inside the wheel cylinder 6 and piping 5 is increased. By repeating the above operations, when the change in the rotational speed of the wheels reaches an appropriate value to stop the wheels,
The brake fluid pressure at that time is maintained until the vehicle stops.

Note that when the controller 12 determines that the brake fluid pressure in the wheel cylinder 6 is too high and that it is necessary to rapidly reduce the brake fluid pressure, the controller 12
However, instead of introducing brake fluid sequentially from the pressure reducing cylinder with a strong spring force to the pressure reducing cylinder with a weak spring force, the adjustment valve 22 is opened from the beginning after introducing the brake fluid into the pressure increase cylinder 14. Brake fluid may also be introduced into the pressure reducing cylinder 24.

When the vehicle is stopped and the brake pedal 2 is released, the on-off valve 4 is first opened by a command from the controller 12 based on a signal from the pedal sensor IO, and then the adjustment valves 20 and 21 are opened.
．． 22 is opened for a certain period of time, and the brake fluid sealed in the pressure reduction cylinders 17, 18.
19 springs 26 push it back into the pipe 5 in preparation for the next braking. In this case, the regulating valve 13 may be in an open state, or may be in a closed state, with high pressure brake fluid being filled in the pressure increasing cylinder 14.

Note that when the brake fluid flows into the pressure reducing cylinder 17.18.19 or is discharged from the pressure increasing cylinder 14, the pressure reduction cylinder 17.18.19. It may be possible to allow sufficient time to elapse until the brake fluid pressure in the pressure increase cylinder 14 and the brake fluid pressure in the wheel cylinder 6 and piping 5 are balanced.
During the change in brake fluid pressure, the adjustment valve +3.20,
21° 22 or close these regulating valves 13, 20, 21.
It is also possible to take a method of repeatedly opening and closing the regulating valve, such as keeping the valve 22 open for a certain period of time.

Next, changes in brake fluid pressure during operation of this device will be explained based on FIGS. 2 and 3. In Figure 2,
The change in brake fluid pressure and internal volume between the on-off valve 4 and the wheel cylinder 6 is represented by the diagram QW, and similarly, the relationship between the brake fluid pressure and the amount of brake fluid sealed in the pressure reducing cylinder 17 is represented by Qc+. The relationship between the brake fluid pressure and the amount of brake fluid sealed in the pressure reducing cylinder 18 is expressed as Qc.
The relationship between the brake fluid pressure sealed in the pressure reducing cylinder I9 and the brake fluid ■ is represented by QC3, and the relationship between the brake fluid pressure sealed in the pressure increasing cylinder 14 and the amount of brake fluid is represented by Qco.

The spring 26 of the pressure reducing cylinder I7 is compressed by an initial load corresponding to the brake fluid pressure Pc+, and no initial load is applied to the spring of the pressure increasing cylinder 14.

When braking starts, the brake fluid pressure reaches P. When the on-off valve 4 is closed and the adjustment valve 20 is opened, the wheel cylinder 6
Brake fluid in an amount of ΔQ flows into the pressure reducing cylinder 17 from the side, and the brake fluid pressure becomes P.

The brake fluid pressure in the wheel cylinder 6 and the brake fluid pressure in the pressure reducing cylinder 17 are then balanced.

Next, the adjustment valve 20 is closed, and the adjustment valve 13 is opened (and the brake fluid in the amount of ΔQ flows from the pressure increase cylinder 14 into the wheel cylinder 6, and the brake fluid pressure in the wheel cylinder 6 is increased by the brake fluid pressure P). The hydraulic pressure and the brake hydraulic pressure in the pressure increasing cylinder 14 are balanced.

As described above, when the pressure of the brake fluid between the on-off valve 4 and the wheel cylinder 6 is repeatedly increased and decreased, the amount of brake fluid in the pressure reducing cylinder 17 is Q'c+, Q"c+, Q"
c+ +..., the amount of brake fluid in the pressure increasing cylinder 14 is Q'co, Q"co, Q"C0...
Changes to If we rewrite the above relationship between brake fluid pressure and fluid volume during operation as a relationship between time and brake fluid pressure, it will become as shown in Fig. 3, and the brake fluid pressure in the wheel cylinder 6 will be P I, P iP 'x, P 4.・・・・・・
Changes to

Here, if the braking force becomes larger than the force that tries to rotate the wheel due to the frictional force between the wheel tire and the road surface, the rotation of the wheel will suddenly decelerate, and if this deceleration exceeds a certain value, the wheel will rotate. locks. The brake fluid pressure (hereinafter referred to as
The maximum brake fluid pressure when the wheels are locked is expressed as Ps. If the brake fluid pressure is Ps, then this brake fluid pressure P
The wheel rotation speed is adjusted as described above to maintain the point P1 below s+ that is closest to the brake fluid pressure Ps, that is, the brake fluid pressure in the wheel cylinder 6 that exerts the maximum braking force that does not cause the wheels to lock. Based on the signal obtained from the sensor 9, optimal control is performed by commands from a controller 12 installed in the vehicle.

Similarly to the above, the maximum brake fluid pressure when the wheels are locked is P s2
．． When P s, , the brake fluid pressure Pe, P2 in the wheel cylinder 6 that exerts the maximum braking force that does not cause the wheels to lock becomes the final brake fluid pressure in the wheel cylinder 6 controlled by this device. .

In addition, when the maximum brake fluid pressure at the time of wheel lock is PS4, by closing the adjustment valve 20 and opening the adjustment valve 21, the brake fluid in the wheel cylinder 6 exerts the maximum braking force that does not cause the wheels to lock. Pressure pt+ can be obtained by this device. That is, when the brake fluid pressure in the wheel cylinder 6 is Pl, the controller 12 determines that this fluid pressure is too high and issues a command to open the regulating valve 21.

Further, the wheel rotation speed sensor 9 indicates the brake fluid pressure P. Detecting the wheel deceleration value at the point and sending the signal to the controller 12, the controller 12 determines that it is necessary to rapidly reduce the brake fluid pressure in the wheel cylinder 6, and relays the brake fluid pressure P. In other words, the adjustment valve 20 or 21 may be opened from the beginning without opening the adjustment valve 13.

Further, in the first embodiment, the regulating valve 13.20
, 21, 22 are opened to introduce brake fluid into the pressure increasing cylinder 14 or the pressure reducing cylinders 17, 18, 19, but the present invention is not limited thereto. Instead of the decompression cylinders 17, 18, and 19, an accumulator made of a rubber bag and filled with gas is housed in a sealed container made of a rigid body so as to be expandable and deflated.
Pressure oil may be introduced into a sealed chamber (variable volume chamber) formed between the rubber accumulator and the rigid sealed container.

Further, in the embodiment, the regulating valve 20 and the pressure reducing cylinder 17 are separated, and the regulating valve 21 and the pressure reducing cylinder 18 are separated.
Although the regulating valve 22 and the pressure reducing cylinder 19 are made separate bodies, the present invention is not limited to this. The cylinder 18 and the cylinder 18 may be configured integrally with each other.

FIG. 4 shows a valve/cylinder assembly 31 in which the regulating valve and variable volume chamber of the above embodiment are integrally constructed.

In FIG. 4, 32 is a support body, and 33 is a case of the valve/cylinder structure 31. In the center of the case 33,
A fixing member 36 consisting of a large diameter portion 34 and a small diameter portion 35 is fixedly attached.

A recess 37 is formed at one end of the fixing member 36, and a recess 38 is formed at the other end. The recess 37 and the recess 38 are communicated through a passage 39. The recess 37 has a recess 40. A disk 42 having a center hole 41 is tightly fitted.

One end of a core 43 whose central flange is fitted into the case 33 is tightly fitted into the recess 40 .

The other end of the core 43 protrudes from the case 33.

A coil 44 is wound around one end of the core 43 .

45.46 is the 0 ring. Further, a recess 47 is formed at one end of the core 43, and this recess 47 is communicated with the outside of the other end of the core 43 through a T-shaped passage 48 provided within the core 43.

The recess 37 of the fixed foot member 36 and the center hole 4 of the disc 42
A valve body 49 is movably fitted into the valve body 1 . A valve seat is provided at one end of the valve body 49, and a valve body 50 is provided between the valve seat and the passage 39. Also,
A passage 51 is formed in the valve body 49 . A spring 52 is provided between the recess 47 of the core 43 and the valve body 49 so as to bias the valve body 50 toward the passage 39 side.

Further, a piston 53 is slidably fitted into the four parts 38 of the fixed member 36, and a hole 54 is formed at one end of the piston 53, and a four part 55 is formed at the other end. A cup-shaped spring receiver 56 is fitted into the small diameter portion 35 of the fixing member 36 . A rod 57 located at the center of the spring receiver 56 is attached to the spring receiver 56 , and the rod 57 is fitted into the hole 54 .

On the other hand, a piston stopper 58 is fixed to the bottom of the case 33, and a spring 59 is provided between the piston stopper 58 and the spring receiver 56. This spring 59 urges the piston 53 toward the valve body 50 via the spring support 56 and rod 57. 60 is a sealing member.

The other end of the core 43 is tightly fitted into the support body 32, and is screwed and attached with a nut 61. A passage 62 communicating with the core 43 is formed in the support member 32 .

Next, the valve/cylinder structure 31 configured as described above
The operation when this is used for the regulating valve 20 and the pressure reducing cylinder 17 will be explained. When the coil 44 is energized in a state where the hydraulic pressure in the passage 62 is higher than the pressure in the recess 55, the valve body 49 is attracted to the side of the core 43 facing the four valve bodies against the force of the spring 52. Pressure oil flows from the passage 62 through the passage 48° recess 47 into the center hole 41 of the disc 42, and further flows through the passage 5I between the bottom of the recess 37 and the valve body 49, and then flows into the valve body 50. push up.

As a result, the pressure oil passes through the passage 39, pushes down the piston 53 against the force of the spring 59, and is stored between the four parts 38.degree. 55.

When the coil 44 is de-energized, the force of the spring 52 causes the valve body 49 to close.
closes the passage 39 via the valve body 50.

When the brake pedal 2 is released and the hydraulic pressure in the pipe 5 is lower than the pressure in the recess 55 (when the coil 44 is energized again, the force of the spring 59 causes the piston 53 to move through the spring receiver 56 and rod 57). Push up the recess 38,
Pressure oil between passages 39, 51. Recessed portion 473 passage 48
．． 62 and returns to the piping 5.

Note that this valve cylinder structure 31 can be used not only as the other valves and pressure reducing cylinder described in the above embodiments, but also as the valve I3 and the pressure increasing cylinder 14.

"Effects of the Invention" According to the present invention, a sensor that detects the rotational speed of a wheel;
A controller that calculates the rotational speed of the wheel and the rate of change in the rotational speed of the wheel from the signal of this sensor, and issues a brake force adjustment command based on the results, and a controller that increases the brake fluid pressure based on the command from the controller; 17h-1 --Dingichiriki↓
In the brake device, the actuator includes an on-off valve that opens and closes a brake fluid passage between a master cylinder and a wheel cylinder, and an on-off valve that is interposed between this on-off valve and the wheel cylinder. and a plurality of variable volume chambers each having a predetermined spring pressure and connected to each of the plurality of regulating valves. is not required, the mechanism is simple, and the anti-lock brake device can be provided at low cost. Furthermore, since the pump can be omitted, part of the engine output or battery power is not consumed, making it economical.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the present invention in which an electric circuit is added to a hydraulic circuit, Fig. 2 is a hydraulic characteristic diagram showing the relationship between the hydraulic pressure and the liquid volume during operation, and Fig. 3 is a diagram of the hydraulic circuit. A hydraulic pressure characteristic diagram showing the relationship between hydraulic pressure and time during operation, and FIG. 4 is a longitudinal sectional view of an integrated regulator valve of the present invention and a cylinder having a variable volume chamber. I... Master cylinder, 2... Brake pedal, 3.5... Piping, 4... Open/close valve (solenoid valve), 6... Wheel cylinder, 7,1
5...Check valve, 8, 16...Bypass passage, 9...Wheel rotation speed sensor, 10...
...Pedal sensor, I la, I lb, 23...
...Signal line, 12...Controller, 13,20
．． 21. 22...Adjusting valve (electromagnetic valve), 14...
Pressure increase cylinder (variable capacity chamber for Masuda), +7.18.
19... Cylinder for pressure reduction (variable volume chamber for pressure reduction)
, 28... Actuator.

Claims (1)

[Claims] A sensor that detects the rotational speed of the wheel, a controller that calculates the rotational speed of the wheel and the rate of change in the rotational speed of the wheel from the signal of this sensor, and issues a brake force adjustment command from the results, and a controller that issues a brake force adjustment command based on the results. In an anti-lock brake device having an actuator that increases or decreases hydraulic pressure, the actuator includes an on-off valve that opens and closes a brake fluid passage between a master cylinder and a wheel cylinder, and an on-off valve that opens and closes a brake fluid passage between a master cylinder and a wheel cylinder; The anti-static valve is characterized by comprising a plurality of regulating valves interposed therein which are normally closed and opened by a command from the controller, and a plurality of variable volume chambers each having a predetermined spring pressure and respectively connected to the plurality of regulating valves. Lock brake device.