JP3221906B2 - Anti-skid brake system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid brake device for a vehicle which suppresses excessive braking force during braking of the vehicle, and more particularly to a hydraulic pump for pumping brake fluid to the master cylinder when the master cylinder is depressurized. It is concerned with the improvement of provisions.

[0002]

2. Description of the Related Art Conventionally, a vehicle may be equipped with an anti-skid brake device (ABS) for preventing a locked or skid state of a wheel from occurring during braking. This kind of anti-skid brake device
For example, as disclosed in Japanese Patent Application Laid-Open No. 3-65464, a control valve is provided between a master cylinder and a wheel cylinder of a wheel to increase or decrease the pressure of the wheel cylinder, and detects a rotational speed of the wheel. A wheel speed sensor for switching the control valve by duty control based on the wheel speed detected by the wheel speed sensor during braking, thereby applying a braking force in accordance with a wheel slip state. This prevents the wheels from being locked or skid during sudden braking, so that the vehicle can be stopped at a distance as short as possible without losing directional stability.

In such an anti-skid brake device, in order to replenish the brake fluid to the master cylinder side, the brake fluid in the wheel cylinder is directly pumped to the master cylinder by a hydraulic pump when the wheel cylinder is depressurized. Alternatively, the brake fluid in the wheel cylinder is temporarily stored in a reserve tank, and the brake fluid in the reserve tank is pumped to the master cylinder by a hydraulic pump when the pressure in the wheel cylinder is reduced.

[0004]

However, the pumping of the brake fluid to the master cylinder by the hydraulic pump is performed against the hydraulic pressure on the master cylinder side generated in response to the driver's brake pebble depression force. Because
A considerably large pressure is required, and a large pulsation is likely to occur at the time of pumping in proportion to the magnitude of the pressure. This pulsation will be transmitted to the driver's foot via the brake pedal,
There is a problem of giving discomfort.

[0005] On the other hand, the operation of the ABS may be sufficient only by slightly depressurizing the wheel cylinder, or may be started due to irregularities on the road surface. Has sufficient brake fluid in the master cylinder. Therefore, it is not always necessary to operate the hydraulic pump immediately after the start of depressurization of the wheel cylinder to pump brake fluid to the master cylinder.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to operate a hydraulic pump with a delay of a predetermined time from the start of pressure reduction of a wheel cylinder to pump brake fluid to a master cylinder. In this way, it is necessary to provide an anti-skid brake device for a vehicle that can minimize the occurrence of discomfort to the driver due to pulsation during pumping while appropriately replenishing the brake fluid to the master cylinder. Is what you do.

[0007]

Means for Solving the Problems To achieve the above object, the inventions according to claims 1 to 3 have the same basic
As constituent elements, as a vehicle anti-skid brake device, a control valve that is provided in a brake pipe that communicates a master cylinder and a wheel cylinder of a wheel to increase or decrease the pressure of the wheel cylinder, A reserve tank for temporarily storing the brake fluid from the wheel cylinder, a hydraulic pump for pumping the brake fluid in the reserve tank to the master cylinder via the brake pipe, and a predetermined time delay from the start of the pressure reduction of the wheel cylinder Pump control means for controlling the hydraulic pump to operate.

Here, when the vehicle speed is high, it is more necessary to suppress an excessive braking force due to the operation of the ABS than when the vehicle speed is low. Therefore, the brake fluid in the reserve tank is relatively controlled so as not to hinder the operation of the ABS. It is necessary to feed the master cylinder early.

Therefore, the invention according to claim 1 is based on the basic
In addition to the basic structural requirements, a vehicle speed detecting means for detecting the vehicle speed, and a hydraulic pump from the time of the start of the pressure reduction of the wheel cylinder by the pump control means as compared with when the vehicle speed detected by the vehicle speed detecting means is low when the vehicle speed is low. Correction means for correcting so as to shorten the time for delaying the operation of the device
It is assumed that.

On the other hand, when the coefficient of friction of the road surface is high,
Since the operation of the ABS is performed in a state where the brake pedal is strongly depressed as compared to when the brake fluid is low, it is considered necessary to pump the brake fluid in the reserve tank to the master cylinder relatively early. On the other hand, when the coefficient of friction of the traveling road surface is low, the ABS operation is performed more frequently than when the friction coefficient is high, so it may be necessary to pump the brake fluid in the reserve tank to the master cylinder relatively early.

The invention according to claim 2 is based on the former idea, and in addition to the above-mentioned basic components,
Furthermore, the road surface friction coefficient detecting means for detecting the friction coefficient of the traveling road surface, and the pump control means as compared with when the road surface friction coefficient detected by the road surface friction coefficient detecting means is low when it is low.
Correction method to correct the time to delay the operation of the hydraulic pump from the time when the pressure reduction of the wheel cylinder is started
And a step .

Meanwhile, the invention of claim 3, wherein this section of the specification standing latter idea, in addition to the basic configuration requirements described above, further, the road surface friction coefficient detecting means for detecting a road surface friction coefficient When the road surface friction coefficient detected by the road surface friction coefficient detection means is low , the pump control is more effective than when the road surface friction coefficient is high.
The control means corrects the time to delay the operation of the hydraulic pump from the start of decompression of the wheel cylinder so as to shorten the time.
And a correction unit .

[0013]

The structure of the action above, in the present invention 1-3 wherein, in the reduced pressure at the wheel cylinder by switching the control valve, together with the brake fluid from the wheel cylinder is once reserved in the reserve tank, the pump control means Based on the control, the hydraulic pump operates with a delay of a predetermined time from the start of the pressure reduction of the wheel cylinder, and the brake fluid in the reserve tank is pumped to the master cylinder via the brake pipe.

In particular, according to the first aspect of the present invention,
Operation of the hydraulic pump is delayed
Correction time is changed according to vehicle speed by correction means
Therefore, replenishing the brake fluid to the master cylinder and discomfort
Prevention can be performed more appropriately.

According to the second and third aspects of the present invention,
For example, the hydraulic pump
The time to delay the operation is adjusted by the correction means to the road surface friction coefficient.
Brake fluid to the master cylinder
Can be carried out and of replenishment and the prevention of discomfort better
You.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1FL indicates a front left wheel, 1FR indicates a front right wheel, 1RL indicates a rear left wheel, and 1RR indicates a rear right wheel. Reference numeral 2 denotes an engine mounted horizontally on the front part of the vehicle body. The generated torque of the engine 2 is sequentially transmitted to the clutch 3, the transmission 4 and the differential device 5, and then the left drive shaft 6L
Via the left front wheel 1FL and the right drive shaft 6R
To the right front wheel 1FR. As described above, in the vehicle, the front wheels 1FL, 1FR are used as drive wheels, and the rear wheels 1RL, 1RL are used.
1RR is a front wheel drive vehicle that is a driven wheel.

7FL, 7FR, 7RL, 7RR are brakes mounted on the wheels 1FL to 1RR, and the brakes 7FL, 7FR, 7RL, 7RR are:
It comprises a disc brake having a hydraulic wheel cylinder 7a. Reference numeral 8 denotes a master cylinder as a brake fluid pressure source, which is a tandem type having two discharge ports 8a and 8b. A brake pipe 13 extends from one discharge port 8a of the master cylinder 8, and the brake pipe 13 is branched into two on the way. One branch pipe 13F is connected to the wheel cylinder 7a of the left front wheel brake 7FL, and the other branch pipe 13R is connected to the wheel cylinder 7a of the right rear wheel brake 7RR. Also, the other discharge port 8b of the master cylinder 8
A brake pipe 14 extends from the brake pipe, and the brake pipe 14 is also branched into two, one branch pipe 14F is connected to the wheel cylinder 7a of the right front wheel brake 7FR, and the other branch pipe 14R is connected to the left rear wheel. Is connected to the wheel cylinder 7a of the brake 7RL.

The above four branch pipes 13F, 13R, 14
F, 14R, branch pipe 1 for front wheels, that is, for drive wheels
3F and 14F are provided with electromagnetic hydraulic control valves 15L and 15L, respectively.
15R, a branch pipe 1 for a rear wheel, that is, for a driven wheel.
3R and 14R have electromagnetic on-off valves 16L and 16L, respectively.
R is connected. The hydraulic control valves 15L, 15R
Is a pressure increasing position for supplying brake fluid pressure (oil pressure) from the master cylinder 8 to the wheel cylinders 7a of the brakes 7FL and 7FR to increase the pressure in the wheel cylinders 7a, and the brake fluid pressure in the wheel cylinders 7a. To the reserve tanks 22L, 22R via the pipes 21L, 21R.
The pressure is switched to the decompression position where the pressure is reduced. The brake fluid stored in the one reserve tank 22L is supplied by the hydraulic pump 23L through the pipe 25L provided with the check valve 24L and the brake pipe 13 at a pressure equal to or higher than the hydraulic pressure in the pipe 13. The master cylinder 8
And sent back. Similarly, the other reserve tank 2
The brake fluid stored in the 2R is also fed back to the master cylinder 8 by the hydraulic pump 23R via the brake pipe 14 and the pipe 25R provided with the check valve 24R.

Further, reference numeral 12 denotes a brake pedal,
The depression force of the brake pedal 12 is transmitted to the master cylinder 8 via a booster, that is, a brake booster 11. The brake booster 11 is basically the same as a known vacuum booster. However, at the time of ABS control, the brake booster 11 has a boosting action even when the brake pedal 12 is not depressed, as described later. Is configured to do so.

The brake booster 11 has a case 31 fixed to the vehicle body and the master cylinder 8. Inside the case 31, a first chamber 34 is formed by a diaphragm 32 and a valve body 33 fixed thereto. And the second
A chamber 35 is defined. The first chamber 34 is always supplied with a negative pressure (for example, the negative pressure of the intake air of the engine 2). When the brake pedal 12 is not depressed, the second chamber 35 is communicated with the first chamber 34, and the operation of the brake booster 11 is stopped. On the other hand, when the brake pedal 12 is depressed, the atmospheric pressure is supplied to the second chamber 35, whereby the diaphragm 32 is displaced forward together with the valve body 33, and a boosting action is performed.

The switching between the negative pressure supply and the atmospheric pressure supply to the second chamber 35 is basically performed by a valve device provided in the valve body 33. The valve body 33 will be described with reference to FIG.

That is, in FIG.
3 is a power piston 4 fixed to the diaphragm 32
1 and a recess 41 formed in the power piston 41
The reaction disk 42 and the base end of the output shaft 43 are fitted in a. The output shaft 43 serves as an input shaft of the master cylinder 8. A valve plunger 45 is mounted in the valve body 33 at the tip of the input shaft 44 connected to the brake pedal 12. A vacuum valve 46 is provided behind the valve plunger 45.

A pressure introducing passage 50 is formed in the power piston 41, and the pressure introducing passage 50 is always communicated with a space 51 formed around the valve plunger 45. The space 51 is always in communication with the second chamber 35. A valve seat 47 on which the vacuum valve 46 is seated is formed at an open end of the pressure introduction passage 50 toward the space 51. The vacuum valve 46 is also seated on a valve seat 45a formed at the rear end of the valve plunger 45. Reference numerals 48 and 49 denote springs for urging the vacuum valve 46 in a direction for seating the same on the valve seat 45a.

In the above configuration, it is assumed that a negative pressure is now introduced into the pressure introducing passage 50. In this state, when the brake pedal 12 is not depressed, the vacuum valve 46 is seated on the valve seat 45a by the urging force of the springs 48, 49 in the state of FIG.
7 are separated. Therefore, the negative pressure from the pressure introduction passage 50 is introduced into the second chamber 35 via the space 51, and no boosting action is performed.

On the other hand, when the brake pedal 12 is depressed from such a state, the input shaft 44 and, consequently, the valve plunger 45 move forward (to the left in the drawing). During this movement, the vacuum valve 46 is first seated on the valve seat 47 and
And the pressure introduction passage 50 are cut off.
6, the valve seat 45a is separated. When the vacuum valve 46 and the valve seat 45a are separated from each other, the atmospheric pressure from the rear of the valve body 33 is introduced into the space 51, and the second chamber 35
Becomes atmospheric pressure. As a result, the diaphragm 32 is displaced forward together with the valve body 33, and as a result, the output shaft 4
3 moves forward and a boosting action is performed. The brake reaction from the master cylinder 8
Is transmitted to the valve plunger 45 and eventually to the brake pedal 12. When the depressing operation force of the brake pedal 12 is released, the state is returned to the state shown in FIG.

The parts described above are the same as those of the known vacuum booster. However, in this embodiment, the ABS is controlled for ABS control.
The pressure introduction passage 50 can be switched between a state in which the negative pressure of the first chamber 34 is introduced and a state in which the atmospheric pressure is introduced. That is, the first chamber 34 and the pressure introduction passage 50 are connected via the pipe 37,
Is provided with an electromagnetic three-way switching valve 38 (see FIG. 1). The switching valve 38 connects the pressure introduction passage 50 to the first
The chamber 34 communicates with the chamber 34 to introduce atmospheric pressure into the pressure introducing passage 50 at the time of excitation. When the switching valve 38 is excited and atmospheric pressure is introduced into the pressure introducing passage 50,
The space 51 and thus the second chamber 35 are provided with the brake pedal 1.
Even if the stepping operation 2 is not performed, the pressure becomes the atmospheric pressure, whereby a boosting action is performed to generate the brake fluid pressure in the master cylinder 8.

FIG. 3 shows an anti-skid brake device (AB
3 is a simplified diagram showing the control system of S). In the figure, reference numerals 61 to 64 denote wheel speed sensors for detecting the rotation speed of each of the wheels 1FL to 1RR. Here, the rear wheel 1 as a driven wheel
Since the rotation speed of RL, 1RR is proportional to the vehicle speed (also referred to as vehicle speed or vehicle speed), the rear wheels 1RL, 1RR
The wheel speed sensors 63 and 64 for detecting the rotation speed of the RR are:
It also has a function as a vehicle speed detecting means for detecting the vehicle speed.
66 and 67 are brake switches that are activated when the brake pedal 12 is depressed, respectively.
For example, one switch is normally open and the other is normally closed. These sensors 61 to 64 and switch 66,
The signal of 67 is input to a control unit 71 configured using a microcomputer.

The control unit 71 detects a road surface friction coefficient μ based on an average value of vehicle speed detected by the wheel speed sensors 63 and 64 on the rear wheel side and a vehicle acceleration which is a derivative thereof. By switching the friction coefficient detecting means 72 and the hydraulic control valves 15L, 15R, the front wheels 1FL, 1F
R brakes 7FL, 7FR (wheel cylinder 7
ABS control means 73 for increasing or decreasing the brake fluid pressure in a)
And pump control means 74 for controlling the operation of the hydraulic pumps 23L and 23R. ABS control means 73
As is known, the various sensors 61 to 64, 6
6 and 67 and the road surface friction coefficient μ detected by the road surface friction coefficient detection means 72, the hydraulic control valves 15L and 15R are switched by duty control during braking to control the front wheels 1FL and 1FR. A braking force is applied according to the slip state, thereby preventing the locked or skid state of the front wheels 1FL, 1FR during sudden braking, and stopping the vehicle at a distance as short as possible without losing directional stability. It is configured as follows. In addition, AB
Prior to the switching control of the hydraulic control valves 15L and 15R, that is, the ABS control, the S control means 73 excites the switching valve 38 and introduces the atmospheric pressure into the pressure introducing passage 50.

On the other hand, the pump control means 74, which is a feature of the present invention, controls the operation of the hydraulic pumps 23L and 23R according to the control flow shown in FIG.

That is, in FIG. 4, after starting, first, in step S1, the ABS control means 7 is started.
It is determined whether or not the ABS control is being performed based on the signal of No. 3 and whether or not the brake fluid pressure of the brakes 7FL and 7FR (wheel cylinder 7a) has started to be reduced in step S2. If one of the determinations in steps S1 and S2 is NO, the routine immediately returns.
If both the determinations are YES, it is further determined in a step S3 whether or not the flag F = 1. Here, the flag F = 1 means that the reserve tanks 22L and 22R are in a so-called full state in which the brake fluid is filled,
The flag F = 0 means that the reserve tanks 22L and 22R are empty.

When the determination in step S3 is NO, ie, when the flag F = 0, that is, when the reserve tanks 22L, 22
When the 2R is empty, the flag F is set to "1" in step S4, and in step S5, whether the vehicle speed v detected by the rear wheel speed sensors 63, 64 is higher than a predetermined vehicle speed vt. Is determined. When the determination is YES or more than the predetermined vehicle speed vt, it is determined in step S6 whether or not the elapsed time T from the decompression start time exceeds the predetermined time T1, and if so, the hydraulic pumps 23L and 23R are determined in step S7. Starts the operation of the reserve tank 22
The brake fluid in L, 22R is pumped to master cylinder 8 via brake pipes 13, 14. Subsequently, in step S8, "0" meaning an empty state is set in the flag F, and the process returns.

When the determination in step S5 is equal to or less than the predetermined vehicle speed vt of NO, it is determined in step S9 whether the elapsed time T from the start of pressure reduction exceeds the predetermined time T2. The predetermined time T2 is set to a value (T2> T1) that is longer than the predetermined time T1 in the determination in step S6. If the predetermined time period T2 has been exceeded, the process proceeds to step S7, where the hydraulic pumps 23L, 23
3R operation is started. When it is determined whether or not the elapsed time T from the decompression start time exceeds the predetermined times T1 and T2, in addition to actually measuring the elapsed time T by using a timer, a decompression command signal issued from the ABS control means 73 is also used. From the number of times, it may be determined whether or not the elapsed time T exceeds the predetermined times T1 and T2.

On the other hand, if the determination in step S6 or S9 is NO, that is, if the elapsed time T from the start of pressure reduction does not exceed the predetermined time T1 or T2, it is determined in step S10 whether the ABS control is being performed. judge. If the determination is YES during the ABS control, the process returns to step S5. If the determination is not NO, the brake pedal 12 is released based on the signals of the brake switches 65 and 66 in step S11. Determine whether or not. If the determination is YES, the process proceeds to step S7 to start the operation of the hydraulic pumps 23L and 23R, while if the determination is NO, the process returns.

When the determination in step S3 is YES, that is, when the flag F = 1, that is, when the reserve tanks 22L and 22R are full, the process immediately proceeds to step S7 to start the operation of the hydraulic pumps 23L and 23R.

Next, the operation in the case where the operations of the hydraulic pumps 23L and 23R are controlled in accordance with such a control flow.
The effect will be described.

When the brake fluid pressure of the wheel cylinders 7a of the brakes 7FL and 7FR is reduced by switching the hydraulic control valves 15L and 15R (that is, until the predetermined time T1 or T2 elapses from the start of the pressure reduction), the hydraulic pump is operated. 2
The brake fluid 3L and 23R do not operate, and the brake fluid flowing out of the wheel cylinder 7a remains in the reserve tanks 22L and 22R. Therefore, at the beginning of the depressurization, the driver does not feel uncomfortable due to the pulsation generated when the brake fluid in the reserve tanks 22L, 22R is pressure-fed to the master cylinder 8 via the brake pipes 13, 14, so that the driver can take the ride accordingly. Comfort can be improved.

On the other hand, predetermined time T1, T
If the ABS control is continued until 2 elapses, the operation of the hydraulic pumps 23L and 23R is started immediately after the elapse of the time. Even before the predetermined time T1, T2 has elapsed, the ABS control is stopped and the brake pedal 1 is stopped.
2 is continued, the next time the ABS control is started and the pressure reduction is started, the hydraulic pump 23
When the operation of L and 23R is started, and when the ABS control is stopped and the depression of the brake pedal 12 is released, the operation of the hydraulic pumps 23L and 23R is started immediately. Therefore, since the reserve tanks 22L and 22R do not become full with the brake fluid, the pressure reduction of the wheel cylinder 7a and the ABS control are not hindered.

In addition, the necessity of suppressing the excessive braking force by the ABS control increases as the vehicle speed increases. In the present embodiment, when the vehicle speed v is high, the predetermined time is shorter than when the vehicle speed v is low. Since the setting is short (T1 <T2), the brake fluid in the reserve tanks 22L and 22R is pumped to the master cylinder 8 relatively early. Therefore, the operation of the hydraulic pumps 23L and 23R can be appropriately controlled according to the degree of the necessity, and the replenishment of the brake fluid to the master cylinder 8 and the prevention of discomfort can be achieved at a high level. be able to.

It should be noted that the present invention is not limited to the above-described embodiment, but includes various other modifications.
For example, in the above-described embodiment, the hydraulic pumps 23L, 23L are delayed by a predetermined time from the start of the pressure reduction of the wheel cylinder 7a.
In controlling to start the operation of R, the above-mentioned predetermined time is changed to two speeds at a high vehicle speed and at a low vehicle speed.
It is needless to say that the number of steps may be changed continuously in three or more steps or steplessly in accordance with the size of.

Also, instead of the vehicle speed v, the time for delaying the operation of the hydraulic pumps 23L and 23R from the time when the pressure reduction of the wheel cylinder 7a is started is determined according to the friction coefficient μ of the traveling road surface detected by the road surface friction coefficient detecting means 72. You may comprise so that it may change. This change has two aspects. The first mode is to shorten the time for delaying the operation of the hydraulic pumps 23L and 23R from the time when the pressure reduction of the wheel cylinder 7a is started, when the road surface friction coefficient μ is high, as compared to when it is low. This is because when the road friction coefficient μ is high, the ABS operation is performed in a state where the brake pedal 12 is strongly depressed as compared with when the road friction coefficient μ is low.
This is based on the idea that the brake fluid in the 2L and 22R needs to be pressure-fed to the master cylinder 8 relatively early. On the other hand, in the second mode, when the road friction coefficient μ is low, the time for delaying the operation of the hydraulic pumps 23L and 23R from the time when the pressure reduction of the wheel cylinder 7a is started is shorter than when the road friction coefficient μ is high. This is because when the road friction coefficient μ is low, the ABS operation is performed more frequently than when the friction coefficient μ is high. Therefore, it is necessary to pressure-feed the brake fluid in the reserve tanks 22L and 22R to the master cylinder 8 relatively early. It is based on the concept of

Further, in the above-described embodiment, the present invention is applied to a brake pipe 13F, which communicates the master cylinder 8 with the wheel cylinders 7a of the front wheel brakes 7FL, 7FR.
The case where the control valves 15L and 15R for increasing or decreasing the pressure (brake fluid pressure) in the wheel cylinder 7a are provided only in the wheel cylinder 14F, but all the four wheel cylinders 7a communicate with the master cylinder 8. Brake piping 1
The present invention can be similarly applied to a case where a control valve for increasing or decreasing the pressure (brake fluid pressure) in the wheel cylinder 7a is provided for each of the 3F, 13R, 14F, and 14R.

[0043]

As described above, according to the anti-skid brake system for a vehicle according to the present invention, when the wheel cylinder is depressurized, the brake fluid from the wheel cylinder is temporarily stored in the reserve tank, and the brake fluid is temporarily stored for a predetermined time from the start of depressurization. By operating the hydraulic pump with a delay and pumping the brake fluid in the reserve tank to the master cylinder, the driver is discomforted by the pulsation during the pumping while properly replenishing the brake fluid to the master cylinder. Can be reduced as much as possible, and the riding comfort can be improved.

In particular, according to the first aspect of the invention, the time for delaying the operation of the hydraulic pump from the time when the pressure reduction of the wheel cylinder is started is changed according to the vehicle speed. Prevention of discomfort can be performed more appropriately.

According to the second and third aspects of the present invention, the time for delaying the operation of the hydraulic pump from the time when the pressure reduction of the wheel cylinder is started is changed according to the road surface friction coefficient. Replenishment of the solution and prevention of discomfort can be performed more appropriately.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle anti-skid brake device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a brake booster.

FIG. 3 is a block diagram of a control system of the anti-skid brake device.

FIG. 4 is a flowchart illustrating a control flow of the hydraulic pump.

[Explanation of symbols]

 7a Wheel cylinder 8 Master cylinder 13, 14 Brake pipe 15L, 15R Hydraulic control valve 22L, 22R Reserve tank 23L, 23R Hydraulic pump 63, 64 Wheel speed sensor (vehicle speed detecting means) 72 Road surface friction coefficient detecting means 74 Pump control means

Continuation of the front page (56) References JP-A-5-112234 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/58 B60T 8/48

Claims (3)

(57) [Claims] 1. A control valve provided in a brake pipe for communicating a master cylinder and a wheel cylinder of a wheel, for increasing or decreasing the pressure of the wheel cylinder, and controlling a brake fluid from the wheel cylinder when the wheel cylinder is depressurized. A reserve tank for temporarily storing, a hydraulic pump for pumping brake fluid in the reserve tank to the master cylinder through the brake pipe, and a hydraulic pump with a predetermined time delay from the start of decompression of the wheel cylinder to operate the hydraulic pump and pump control means for controlling so as to, vehicle speed detecting means for detecting a vehicle speed, when low when have been higher speed detected by the vehicle speed detecting means
In comparison, the pump control means
Shorten the time to delay the operation of the hydraulic pump from the start of decompression.
An anti-skid brake device for a vehicle, comprising: a correcting unit that corrects the vehicle so as to make the vehicle lighter. 2. A master cylinder and a wheel cylinder of a wheel.
Installed in the brake pipe that communicates with the
A control valve to increase or decrease the pressure of the cylinder, and from the wheel cylinder when the wheel cylinder is depressurized.
A reservoir tank for temporarily storing the brake fluid of the above , and the brake fluid in the reservoir tank is supplied to the above-mentioned brake piping.
A hydraulic pump for pumping to the master cylinder through the elapsed time from the start of pressure reduction time in the wheel cylinder
When the elapsed time is greater than a predetermined value
Pump system that controls the hydraulic pump to operate
Control means and road surface friction coefficient detecting means for detecting a friction coefficient of a traveling road surface
When, as compared with when low when a high detected road surface friction coefficient by the road surface friction coefficient detection means, shortens the time to delay the operation of the hydraulic pump from the vacuum beginning of <br/> wheel cylinders by the pump control means Correction means for correcting
Antiskid brake apparatus for a vehicle, characterized in that it comprises. 3. A wheel cylinder for a master cylinder and wheels.
Installed in the brake pipe that communicates with the
A control valve to increase or decrease the pressure of the cylinder, and from the wheel cylinder when the wheel cylinder is depressurized.
A reservoir tank for temporarily storing the brake fluid of the above , and the brake fluid in the reservoir tank is supplied to the above-mentioned brake piping.
It said a hydraulic pump for pumping the master cylinder, a predetermined time delayed et the decompression start time of the wheel cylinder via
Pump that controls the hydraulic pump to operate
Control means and road surface friction coefficient detecting means for detecting a friction coefficient of a traveling road surface
If, shorter, the time to delay the operation of the hydraulic pump from the vacuum beginning of <br/> wheel cylinders by the pump control means than when higher when the road surface friction coefficient detected by the road surface friction coefficient detecting means is low Correction means for correcting
An anti-skid brake device for a vehicle, comprising: