JP2900542B2 - Vehicle brake pressure control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle brake pressure control device capable of continuously controlling a brake pressure supplied to a wheel cylinder.

[Conventional technology]

Conventionally, for example, in an anti-skid control device, adjustment of the brake pressure of a wheel cylinder has been performed by switching the communication between a master cylinder (pressure generating source), a wheel cylinder, and a reservoir using a solenoid valve. Particularly, in Japanese Patent Publication No. 51-6308, by driving the solenoid valve with a pulse-like control current,
An anti-skid control device capable of changing an increasing / decreasing gradient of a brake pressure of a wheel cylinder is shown.

[Problems to be solved by the invention]

However, in the above-described conventional anti-skid control device, when the switching between the communication and the cutoff by the electromagnetic valve is performed, an oil hammer phenomenon occurs with the switching. Due to this oil hammer phenomenon, a large pressure pulsation is generated in the brake pressure of the wheel cylinder, and the vibration is transmitted to the vehicle body via a suspension or the like. For this reason, every time switching between communication and cutoff by the solenoid valve, operation noise and vibration of the vehicle body due to the oil hammer phenomenon occur,
There is a problem of giving the driver discomfort. Further, the above-mentioned oil hammer phenomenon also affects the master cylinder, and pressure pulsation occurs similarly to the above. This pressure pulsation causes vibrations in the brake pedal, and has a problem of impairing the driver's brake feeling. The generation of the operation noise and the vibration based on the oil hammer phenomenon as described above remarkably appears particularly when the brake pressure is increased.

Further, the anti-skid control device has been described as a representative example. However, other than the anti-skid control device, there is a similar problem in a device that adjusts the brake pressure of a wheel cylinder using a conventional solenoid valve.

The present invention has been made in view of the above points, and has as its object to provide a vehicle brake pressure control device capable of smoothly increasing the brake pressure of a wheel cylinder.

[Means for solving the problem]

In order to achieve the above object, a vehicle brake pressure control device according to the present invention includes: a wheel cylinder that generates a wheel braking force when a vehicle is braked; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. In the brake pressure control device for a vehicle, a differential pressure between a hydraulic pressure at the hydraulic pressure source and a hydraulic pressure at the wheel cylinder is disposed in a pipeline connecting the hydraulic pressure source and a wheel cylinder, and a current flowing through a solenoid coil And a differential pressure control valve that shuts off the pipeline when the differential pressure is reached.

Also, in a vehicle brake pressure control device including: a wheel cylinder that generates a wheel braking force during braking of a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder, the hydraulic pressure source and the wheel cylinder The flow path diameter of the pipeline is arranged as the differential pressure between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the wheel cylinder approaches a differential pressure corresponding to the amount of current supplied to the solenoid coil. A differential pressure control valve that throttles may be provided.

A vehicle brake pressure control device comprising: a wheel cylinder that generates a wheel braking force at the time of braking of a vehicle; and a hydraulic pressure source that applies hydraulic pressure to the wheel cylinder. A pressure difference between a hydraulic pressure at the hydraulic pressure source and a hydraulic pressure at the wheel cylinder is disposed in a pipeline connecting the hydraulic pressure source and the wheel cylinder, and is set according to a traveling state of the vehicle. And a differential pressure control valve that continuously varies the flow rate of the brake oil between the hydraulic pressure source and the wheel cylinder as the pressure approaches.

According to the above configuration, the hydraulic pressure supplied to the wheel cylinder is controlled by the differential pressure control valve in accordance with the differential pressure between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the hydraulic pressure source.
Therefore, the wheel cylinder pressure is continuously adjusted until the differential pressure is reached.

Further, the wheel cylinder pressure is continuously adjusted even if the flow path diameter of the pipeline is reduced as the pressure difference between the wheel cylinder pressure and the hydraulic pressure generation source in accordance with the amount of electricity supplied to the solenoid approaches.

Similarly, as the differential pressure approaches a differential pressure determined according to the running state of the vehicle, the flow amount of brake oil between the hydraulic pressure source and the wheel cylinder may be continuously varied. good.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment in which the vehicle brake pressure control device of the present invention is used as an anti-skid control device.

In FIG. 1, only one wheel is shown, or the other wheels have the same configuration. In FIG. 1, a differential pressure control valve 100 is provided between pipes 10 and 11 connecting the master cylinder 2 and the wheel cylinder 4.
The differential pressure control valve 100 is for controlling the pressure difference ΔP of the master cylinder pressure P _M and the wheel cylinder pressure _{P W (= P M -P W} ). A normally closed electromagnetic switching valve 7 is provided between pipes 11 and 12 connecting the wheel cylinder 4 and the reservoir 8. That is, the wheel cylinder pressure P _W is increased by the differential pressure control valve 100 and reduced by the electromagnetic switching valve 7. Further, the brake fluid that has flowed out to the reservoir 8 is returned by the pump 9 to the pipe 10 connecting the master cylinder 2 and the differential pressure control valve 100 via the pipe 13.

In addition, 1 is a brake pedal, 3 is a brake booster,
5 is a wheel, and 6 is a wheel speed sensor for detecting the wheel speed of the wheel 5. The detection signal of the wheel speed sensor 6 is input to an electronic control unit (ECU) 20. The ECU 20 calculates the locking tendency of the wheel 5 based on the detection signal, and calculates the differential pressure control valve.
A drive signal for driving the electromagnetic switching valve 7 and the pump 9 is output to control the wheel cylinder pressure _PW .

FIG. 2 shows the structure of the differential pressure control valve 100. Differential pressure control valve 100
Are the core 101, the yoke 102, and the plate 10
3, mainly composed of an armature 104, a cylindrical body 103a of a non-magnetic material brazed to the plate 103, a washer 106 of a non-magnetic material, and an electromagnetic coil 114 molded with resin.
The armature 104 is slidably assembled in the cylindrical body 103a. When the electromagnetic coil 114 is excited, the armature 104 moves toward the core 101 by its electromagnetic attraction. Then, the ball 105 fixed to the armature 104 is seated on the seat portion 111 formed in the core 101, and the flow path 1 communicating with the pipe 10
The communication between 01a and the room 112 is cut off. On the other hand, the electromagnetic coil 114
Armature 104 is spring 1
08a and 108b receive a biasing force in a direction to open the sheet portion 111, and are stationary at a position where they come into contact with the washer 106.
A hole 107 is formed in the armature 104 so that the chamber 11
2 and the chamber 113 are communicated. Reference numeral 110 denotes an O-ring.

Next, the operation of this embodiment will be described with reference to FIGS.

(I) During Normal Braking During normal braking, the ECU 20 does not output a drive signal to either the differential pressure control valve 100 or the electromagnetic switching valve 7. For this reason, the differential pressure control valve 100 makes the master cylinder 2 and the wheel cylinder 4 communicate with each other, and the electromagnetic switching valve 7 makes the communication between the wheel cylinder 4 and the reservoir 8 shut off. Therefore, the master cylinder pressure P generated when the driver depresses the brake pedal 1
_M is directly transmitted to the wheel cylinder 4 via the pipe 10, the differential pressure control valve 100, and the pipe 11.

(Ii) At the time of anti-skid control When the locking tendency of the wheels 5 becomes stronger due to the braking operation during running, the anti-skid control is started, and the wheel cylinder pressure P _W is controlled by the differential pressure control valve 100 and the electromagnetic switching valve 7.
Is adjusted.

Here, when the pressure is increased, the electromagnetic switching valve 7 is not supplied with a drive signal, and the wheel cylinder pressure _PW is increased according to the current value supplied to the differential pressure control valve 100. The state is the third
This will be described with reference to the drawings.

When a current is applied to the electromagnetic coil 114 of the differential pressure control valve 100 to be excited, the ball 105 of the armature 104
An electromagnetic attraction force _FE is generated in the direction of sitting on the vehicle. Here, the armature 104 three forces in addition to the electromagnetic attractive force F _E is acting. That is, as the first force, the spring force F _S is constantly acting on the armature 104 in the direction of opening the seat portion 111 by the springs 108a and 108b. Further, as a second force, the seat area 1 when the ball 105 fixed to the armature 104 is seated on the seat section 111,
Biasing force of the master cylinder pressure P _M in the direction to open the 11
F _M (= P _M × S) is acting. Further, as a third force, a wheel cylinder pressure P _{W with} respect to the seat area S is used.
The force F _W (= P _W × S) by the ball 1 of the armature 104
05 acts on the seat portion 111.

When the force is balanced acting on the armature 104, the ball 105 of the armature 104 is seated on the seat portion 111, the master cylinder P _M and the wheel cylinder pressure P _W at this time are both stable. That is, these four forces
_{F M, F W, F S} , the following equation is obtained from the balance of the F _E.

The _{F M + F S = F W} + F E ... wherein the pressure difference ΔP between the master cylinder pressure P _M and the wheel cylinder pressure P _W is represented by the following equation '.

Here, the spring force F _S is constant, and since the sheet area S is also constant, as the pressure difference ΔP between the master cylinder pressure P _M and the wheel cylinder pressure P _W is shown in FIG. 4, the electromagnetic attraction force F Can be controlled by _E. This electromagnetic attraction force F _E
Is a value proportional to the exciting current _IE of the electromagnetic coil 114. Therefore, by adjusting the excitation current I _E, by controlling the electromagnetic attraction force F _E, the master cylinder pressure P _M and the wheel cylinder
The pressure difference ΔP from P _W can be controlled.

Here, for example, as shown in FIG. 5, the excitation current I _E1
Consider the case where the exciting current is set to I _E2 (I _E2 <I _E1 ) and the electromagnetic attraction force is changed to F _E2 when the above-mentioned differential pressure is ΔP ₁ with (the electromagnetic attraction force F _E1 ). The reduction in the electromagnetic attraction force F _E, unbalanced forces acting on the armature 104,
The force for urging the armature 104 in the sheet opening direction is larger. Therefore, the armature 104 moves in the direction of the washer 106, the seat portion 111 is opened, and the brake fluid flows from the master cylinder 2 into the wheel cylinder 4. As a result, the wheel cylinder pressure _PW increases, and the urging force _FW due to the wheel cylinder pressure _PW increases. As the differential pressure [Delta] P is shown in FIG. 4, when reduced to the differential pressure [Delta] P ₂ corresponding to the electromagnetic attracting force F _E2, the force acting on the armature 104 are balanced. As a result, the ball 105 is seated on the seat portion 111 again, and the wheel cylinder pressure P _W becomes (P _M −
P ₂ ).

Here, in the present embodiment, the sum K (= Ka + Kb) of the spring constants Ka and Kb of the springs 108a and 108b of the differential pressure control valve 100.
Is the electromagnetic attraction force F _{E with} respect to the armature 104 stroke.
Is set to be larger than the rate of change. Therefore, the differential pressure between the master cylinder pressure P _M and the wheel cylinder pressure P _W delta
P when the approach on the differential pressure [Delta] P ₂ corresponding to the electromagnetic attracting force F _E2, the ball 1 of the armature 104 closer to the differential pressure [Delta] P ₂
05 gradually sits on the seat part 111. Therefore, the ball 105
The flow path between the seat cylinder 111 and the seat portion 111 changes gradually so that the wheel cylinder pressure _PW is smoothly increased as shown in FIG. Therefore, it is possible to reduce the operation noise and vibration generated when the brake pressure is increased.

As described above, the wheel cylinder pressure P _W is set so that the electromagnetic switching valve 7 is not driven and the exciting current _{IE of the} differential pressure control valve 100 is increased.
, The pressure can be increased smoothly.

When the wheel cylinder pressure P _{W is} to be maintained, the electromagnetic switching valve 7 is not driven, and the exciting current I of the differential pressure control valve 100 is maintained.
_E should be maximized. As a result, both the differential pressure control valve 100 and the electromagnetic switching valve 7 are shut off, and the brake fluid does not flow into and out of the wheel cylinder 4, so that the wheel cylinder pressure P _W is maintained.

When reducing the wheel cylinder pressure P _W ,
The electromagnetic switching valve 7 is driven in a state where the exciting current _IE of the differential pressure control valve 100 is maximized, and the electromagnetic switching valve 7 is brought into a communication state. At this time, the brake fluid of the wheel cylinder 4 is
Flows into the reservoir 8 through the circulating air, so that the wheel cylinder pressure _PW is reduced. During the anti-skid control, the pump 9 is driven, and the brake fluid in the reservoir 8 is supplied to the pipe 10.
Is returned to.

Next, the control procedure of the anti-skid control executed by the ECU 20 will be described with reference to the flowchart of FIG. 6 and FIGS. 7 (a) to 7 (e).
This will be described with reference to the time chart of FIG.

In FIG. 6, in step 500, the wheel speed _VW is calculated based on the detection signal from the wheel speed sensor 6.
In step 501, the wheel speed calculated in step 500
Wheel acceleration _W is calculated based on V _W. Step 502
Then, using the wheel speed V _W and the wheel acceleration _W calculated in steps 500 and 501, the estimated vehicle speed V _B and its acceleration _B
Is calculated. In step 503, based on the estimated vehicle speed V _B calculated in step 502, it calculates a reference speed V _S for determining the locking tendency of the wheel. In other words, the estimated vehicle speed V _B and K ₀ times (e.g. K ₀ = 0.7 to 0.95), obtains a speed corresponding to the slip rate to the target, the reference velocity V _S of the minus the offset speed V ₀ from the speed And

_{V S = K 0 · V B} -V 0 ... Here, play the offset speed V ₀ from K ₀ · V _B, even when the estimated vehicle speed V _B becomes smaller, the estimated vehicle speed V _B
This is for giving a speed difference between the reference speed V _S and the reference speed V _S greater than the offset speed V ₀ .

In step 504, based on and the reference speed V _S estimated vehicle acceleration _B which is calculated in step 502 and 503, a parameter representing a locking tendency of wheels (hereinafter, referred to as the wheel parameters) W a is calculated by the following equation.

W = A · (V _W −V _S ) + B · ( _W − _B ) where A and B are positive constants.

The wheel parameter W calculated by the equation indicates that there is no wheel lock tendency when W> 0, and that there is a lock tendency when W <0, and the value of | W | represents the strength of the lock tendency.

In step 505, it is determined whether or not the anti-skid control has already been started. If the control has been started, the process proceeds to step 508, and if not, the process proceeds to step 506.

In step 506, the tendency of the wheels to lock is determined. That is, the wheel parameter W obtained in step 504 is compared with the control start level −K _W (K _W : a positive constant), and W <−K _W
If it is determined that the wheels have a tendency to lock, the process proceeds to step 507. On the other hand, if W- _KW is determined in step 506, it is determined in step 52 that the wheels do not have a locking tendency.
Go to 0.

In step 507, the pump 9 is driven (ON state) to start anti-skid control.

In step 508, it is determined whether or not the state where the wheel parameter W is larger than 0 has continued for Te seconds (for example, 0.5 to 2 seconds). If the result of this determination is affirmative, it is determined that the tendency of the wheels to be locked has been completely suppressed and step 51
Proceed to 9 to end the anti-skid control. That is,
In step 519, the pump 9 is turned off (OFF state), and the power supply to the differential pressure control valve 100 and the electromagnetic switching valve 7 is stopped (OFF state). On the other hand, if the determination result in step 508 is negative, it is determined that the locking tendency of the wheels has not been completely suppressed, and the process proceeds to step 509 to continue the anti-skid control. That is, the pressure increase level wheel parameter W in step 509 K _U: comparing (K _U positive constant) and, if it is determined that W> K _U proceeds to step 511. On the other hand, the process proceeds to step 510 if it is determined that WK _U at step 509. At step 510, vacuum level wheel parameters W -K _D: comparing (K _D positive constant) and, when it is determined that W <-K _D proceeds to step 517, when it is determined that the W-K _D is Proceed to step 515. Here, when the process proceeds to step 511, the pressure increasing process is performed, when the process proceeds to step 515, the pressure maintaining process is performed, and when the process proceeds to step 517, the pressure reducing process is performed. That is, steps 509, 51
By 0, pressure regulation control of the wheel cylinder pressure _PW according to the value of the wheel parameter W is selected.

Target differential pressure [Delta] P _T of the pressure difference [Delta] P in step 511 the master cylinder pressure P _M and the wheel cylinder pressure P _W is calculated.

Here, the target differential pressure ΔP _T is calculated as follows.

Previous <When turned pressure increase from reduced pressure or holding state>, when the target differential pressure when the change in vacuum or holding the pressure increasing state is [Delta] P _TO, [Delta] P the target differential pressure _{ΔP T T = ΔP TO + ΔP} K ... Asking. Here, ΔP _K is a constant (for example, 0 to 10 atm).

<When are continuing to pressure increase> target differential pressure ΔP _T is calculated by the following equation.

ΔP _T = ΔP _{T (n−1)} −K _P · W where ΔP _{T (n−1)} is a target differential pressure calculated one cycle ago, K _P is a positive constant, and W is a wheel parameter. The target differential pressure ΔP _T is calculated according to the magnitude of the wheel parameter W.

In step 512, according to the target differential pressure ΔP _T obtained in step 511, the excitation current value _IE corresponding to the differential pressure control valve 100 corresponding thereto.
Is calculated. In step 513, the exciting current _IE obtained in step 512 is output, and the differential pressure control valve 100 is driven. In step 514, the energizing current value to the electromagnetic switching valve 7 is set to zero, and the electromagnetic switching valve 7 is turned off (OFF state). As described above, the wheel cylinder pressure _PW is increased.

In step 515, the maximum excitation current _IEmax is output to the differential pressure control valve 100, and the differential pressure control valve 100 is turned off. In step 516, the energizing current value to the electromagnetic switching valve 7 is set to zero, the electromagnetic switching valve 7 is de-energized, and the wheel cylinder pressure _PW is held.

In step 517, the maximum excitation current _IEmax is output to the differential pressure control valve 100, and the differential pressure control valve 100 is turned off. In step 518, a predetermined current is supplied to the electromagnetic switching valve 7,
When the electromagnetic switching valve 7 is energized, the wheel cylinder pressure
Decrease P _W.

The flowchart shown in FIG. 6 is, for example, 5 msec.
It is executed every time.

Next, the control of the wheel cylinder pressure _PW executed according to the flowchart of FIG. 6 will be described with reference to time charts of FIGS. 7 (a) and 7 (b).

Figure 7 (a) ~ (e) are each speed V _B in the anti-skid control, V _S, V _W, the wheel parameters W, the target differential pressure [Delta] P _T, the drive signal of the electromagnetic switching valve 7, the master cylinder pressure P _M , The change of the wheel cylinder pressure P _W is shown with time on the horizontal axis.

In Figure 7 (a) ~ (e), the time t ₁ ~t ₂ in the wheel parameter W is larger than the pressure-increasing level K _U, the pressure increasing process is performed. That is, at time t ₁ ~t _2, the target differential pressure [Delta] P _T is calculated according to the formula described above, the target differential pressure [Delta] P _T becomes gradually smaller, the wheel cylinder pressure P _W is increased. Time t ₂ to become the wheel parameter W becomes less pressure increasing level K _U, but becomes as pressure holding process is performed, as described above, a vacuum or holding the target differential pressure [Delta] P _T at this time from the pressure increasing state is stored as a target differential pressure ΔP _tO of time has changed.

Since the time t ₂ ~t ₃ In the wheel parameter W is below the pressure boosting level K _U, and is controlled starting level -K _O or more, the pressure holding process is performed. That is, the maximum exciting current I _Emax is output to the differential pressure control valve 100 (the target differential pressure ΔP _T is maximized in FIG. 7, but this has the same meaning), and the electromagnetic switching valve 7 remains shut off. I do. Since the made the time t ₃ the wheel parameter W is smaller than the control start level -K _b, decompression processing is performed. That is, the maximum excitation current I _Emax is output to the differential pressure control valve 100, and a predetermined current is supplied to the electromagnetic switching valve 7 to bring the electromagnetic switching valve 7 into a communicating state. By this processing, the wheel cylinder pressure ΔP _W is reduced, and the tendency of the wheels to lock is suppressed. The _{reason why the} maximum excitation current I _Emax is output to the differential pressure control valve 100 in the pressure reduction process is that even when the wheel cylinder pressure _PW decreases, the master cylinder 2 receives the wheel cylinder 4 through the differential pressure control valve 100 via the differential pressure control valve 100.
This is to prevent the brake fluid from flowing into the motor. Time t ₄
To become the wheel parameter W is the control start level -K _D above, the pressure holding process is performed again. Time t ₅ to become the wheel parameter W is larger than the pressure-increasing level K _U, the pressure increasing process is performed again. Where the wheel cylinder pressure P _W
There At time t ₅ changes the pressure increase from the holding, the target differential pressure [Delta] P _T is calculated by the above equations. That is, the value obtained by adding ΔP _K (positive constant) to the target differential pressure ΔP _TO at time t ₂ (the time when the pressure was changed from the previous pressure increase to holding) is the target differential pressure Δ at time t _5.
Let it be _PT . As a result, the wheel cylinder pressure _PW quickly increases to near the pressure immediately before the previous pressure reduction. At this time, as the actual differential pressure [Delta] P between the master cylinder pressure P _M and the wheel cylinder pressure P _W approaches the target differential pressure [Delta] P _T, the armature 10
The wheel cylinder pressure _PW is increased smoothly and without pulsation because the pressure is reduced from the flow path area between the fourth ball 105 and the seat portion 111. Target differential pressure [Delta] P _T is calculated according to the equation at time t ₅ ~t ₆ followed.

Here, determine the target differential pressure [Delta] P _T from the [Delta] P _TO at time t _5, and in order to return to the vicinity of the pressure quickly reduced pressure immediately before the wheel cylinder pressure P _W, thereby,
The required braking force can be obtained quickly. In addition, adding the constant ΔP _K to the target differential pressure ΔP _TO when the process was changed from pressure increase to pressure reduction or holding last time, considering the braking efficiency, the optimal pressure is slightly smaller than the pressure immediately before the start of pressure reduction, considering the braking efficiency. It is because it is considered.

That is, the locking tendency is generated in the wheels at the pressure immediately before the pressure reduction, and the maximum pressure at which the locking tendency does not occur (the optimal pressure in the anti-skid control) is a pressure slightly smaller than the pressure immediately before the pressure reduction.

In the first embodiment described above, when the wheel parameters W is smaller than the control start level -K _0, was followed by vacuum wheel cylinder pressure P _W simply by driving the electromagnetic switching valve 7.
However, the decompression speed according to the wheel parameter W may be obtained by performing a gentle decompression by combining the decompression and the holding. In this case, pressure pulsation occurs in the wheel cylinder pressure, but the wheel cylinder pressure is often controlled to be low on a slippery road surface where wheel lock easily occurs. For this reason, the pressure pulsation width accompanying the driving of the electromagnetic switching valve 7 is small, and the operating noise and vibration due to the pressure pulsation are small. Further, the electromagnetic switching valve 7 is replaced by a differential pressure control valve that adjusts the pressure difference ΔP ′ between the wheel cylinder pressure P _W and the pressure of the reservoir 8 so that pressure pulsation does not occur in the wheel cylinder pressure even when the pressure is reduced. Is also good.

In the first embodiment, it had a a [Delta] P _K constant expressions, [Delta] P _K in accordance with the previous pressure reduction time (the 7 Figure t ₄ -t ₃₎
May be changed. That is, when the decompression time is short, ΔP _K is set to a small value, and as the decompression time becomes long, the value of ΔP _K is increased.

In the first embodiment shows an example in which control by the excitation current for energizing the electromagnetic force F _E to the electromagnetic coil 114. However, the drive signal of the electromagnetic coil 114 is a duty signal as shown in FIG. 8, and its duty ratio t / T (for example, 1 msec <T <
100 msec) may be as to control the electromagnetic force F _E by controlling.

Further, the present invention can be used not only in a reflux-type (closed-loop type) anti-skid control device as in the first embodiment but also in a known non-reflux-type (open-loop type) anti-skid control device. I can't tell.

In the above embodiment, an example in which the present invention is applied to an anti-skid control device has been described. However, the present invention is also very effective when applied to a traction control device or a braking force distribution of a normal brake.

〔effect〕

As described above, according to the present invention, it is possible to smoothly increase the brake pressure of the wheel cylinder.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining the structure of the differential pressure control valve shown in FIG. 1, and FIG.
FIG. 4 is an explanatory view for explaining the operation of the embodiment shown in FIG.
FIG. 5 is a characteristic diagram showing characteristics of the differential pressure control valve shown in FIG.
7A and 7B are time charts for explaining the operation of the embodiment shown in FIG. 1, FIG. 6 is a flowchart showing a control procedure of the embodiment shown in FIG. 1, and FIGS. e) is a time chart showing a control result according to the flowchart shown in FIG. 6, and FIG. 8 is a waveform chart showing another example of a drive signal of the electromagnetic coil of the differential pressure control valve. 1 ... Brake pedal, 2 ... Master cylinder, 3 ... Brake booster, 4 ... Wheel cylinder, 5 ... Wheel, 6 ...
Wheel speed sensor, 7 ... Solenoid switching valve, 8 ... Reservoir, 9 ...
Pump, 10,11,12,13 …… Piping, 20 …… Electronic control device (EC
U), 100 …… Differential pressure control valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 8/34-8/86 F16K 31/06

Claims (15)

(57) [Claims] 1. A vehicle brake pressure control device comprising: a wheel cylinder for generating a wheel braking force when braking a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. A differential line between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the wheel cylinder when the differential pressure between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the wheel cylinder becomes a differential pressure corresponding to the amount of current supplied to the solenoid coil. A vehicle brake pressure control device comprising a pressure control valve. 2. A brake pressure control device for a vehicle, comprising: a wheel cylinder for generating a wheel braking force when braking a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. Disposed in a conduit connecting between the cylinder and the cylinder, and as the differential pressure between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the wheel cylinder approaches a differential pressure corresponding to the amount of current supplied to the solenoid coil, A brake pressure control device for a vehicle, comprising a differential pressure control valve for narrowing a flow path diameter. 3. A vehicle brake pressure control device comprising: a wheel cylinder for generating a wheel braking force during braking of a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. Traveling state detecting means, which is disposed in a conduit connecting between the hydraulic pressure source and the wheel cylinder, wherein a differential pressure between a hydraulic pressure at the hydraulic pressure source and a hydraulic pressure at the wheel cylinder varies according to a traveling state of the vehicle. A differential pressure control valve that continuously varies a flow amount of brake oil between the hydraulic pressure source and the wheel cylinder as the differential pressure approaches the predetermined differential pressure. Pressure control device. 4. The valve according to claim 1, wherein the differential pressure control valve is configured to switch the pipe when the differential pressure between the hydraulic pressure at the hydraulic pressure generating source and the hydraulic pressure at the wheel cylinder becomes a differential pressure corresponding to the amount of current supplied to the solenoid coil. The vehicle brake pressure control device according to claim 2 or 3, wherein the road is blocked. 5. A target pressure difference between a hydraulic pressure generated by the hydraulic pressure generation source and a hydraulic pressure supplied to the wheel cylinder is calculated based on a traveling state of the vehicle, and the target differential pressure is calculated with respect to the differential pressure control valve. The vehicle brake pressure control device according to any one of claims 1 to 4, further comprising a control unit configured to supply an amount of electricity according to the differential pressure. 6. A brake pressure control device for a vehicle according to claim 3, wherein a value indicating a tendency of slip of each wheel of the vehicle is detected as the running state of the vehicle. . 7. A normally-open type differential pressure control valve provided between a hydraulic pressure source and a wheel cylinder for continuously adjusting a differential pressure between the hydraulic pressure generated by the hydraulic pressure source and the wheel cylinder. A valve device that is provided between the wheel cylinder and the reservoir and that at least permits and shuts off the communication between the wheel cylinder and the reservoir; a traveling state detection unit that detects a traveling state of the vehicle; and a traveling state detection unit that detects the traveling state. A target differential pressure between a hydraulic pressure generated by the hydraulic pressure generation source and a hydraulic pressure supplied to the wheel cylinder is calculated based on a traveling state of the vehicle, and the target differential pressure is calculated with respect to the differential pressure control valve. And a control unit that outputs a control signal that is turned off when the vehicle brakes. 8. A vehicle brake pressure control device comprising: a wheel cylinder for generating a wheel braking force when braking a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. A second line that is disposed in a line connecting the cylinder and a line that cuts off the line when a differential pressure between a hydraulic pressure in the hydraulic pressure generation source and a hydraulic pressure in the wheel cylinder becomes a differential pressure corresponding to an amount of electricity supplied to a solenoid coil; 1 is provided in a pipe connecting between the wheel cylinder and a reservoir for storing brake oil when the wheel cylinder pressure is reduced, and the difference between the oil pressure in the wheel cylinder and the oil pressure in the reservoir is provided. And a second differential pressure control valve that shuts off the pipeline when the pressure becomes a differential pressure corresponding to the amount of current supplied to the solenoid coil. Brake pressure control system for a vehicle. 9. A brake pressure control device for a vehicle, comprising: a wheel cylinder that generates a wheel braking force during braking of a vehicle; and a hydraulic pressure source for applying a hydraulic pressure to the wheel cylinder. Disposed in a conduit connecting between the cylinder and the cylinder, and as the differential pressure between the hydraulic pressure at the hydraulic pressure source and the hydraulic pressure at the wheel cylinder approaches a differential pressure corresponding to the amount of current supplied to the solenoid coil, A normally open first differential pressure control valve for reducing a flow path diameter, and a wheel cylinder disposed between the wheel cylinder and a reservoir for storing brake oil when the wheel cylinder pressure is reduced, A normally open type in which the flow path diameter of the conduit is reduced as the differential pressure between the hydraulic pressure in the reservoir and the hydraulic pressure in the reservoir approaches a differential pressure corresponding to the amount of current supplied to the solenoid coil. Vehicle brake pressure control device, characterized in that it comprises a second differential pressure control valve, the. 10. A vehicle comprising: a wheel cylinder for generating a wheel braking force when braking a vehicle; and a master cylinder for applying oil pressure to the wheel cylinder, wherein a pipe connecting the master cylinder and the wheel cylinder is provided. A vehicle provided with a differential pressure control valve for reducing a flow diameter of brake oil between the master cylinder and the wheel cylinder in accordance with a differential pressure between the hydraulic pressure in the master cylinder and the hydraulic pressure in the wheel cylinder. Brake pressure control device. 11. A vehicle comprising: a wheel cylinder for generating a wheel braking force when braking a vehicle; and a master cylinder for applying hydraulic pressure to the wheel cylinder, wherein a pipe connecting the master cylinder and the wheel cylinder is provided. A differential pressure control valve that reduces the flow diameter of the brake oil between the master cylinder and the wheel cylinder according to a differential pressure between the hydraulic pressure of the master cylinder and the hydraulic pressure of the wheel cylinder, according to a traveling state of the vehicle. Control means for calculating a target value of the differential pressure between the master cylinder and the wheel cylinder, and controlling to output an energization amount according to the target value to the differential pressure control valve. A brake pressure control device for a vehicle, comprising: 12. A running state detecting means comprising: a wheel cylinder for generating a wheel braking force during braking of a vehicle; a master cylinder for applying a hydraulic pressure to the wheel cylinder; Target differential pressure calculating means for calculating a target differential pressure between a hydraulic pressure in the wheel cylinder and a hydraulic pressure in the master cylinder according to a traveling state; and a difference between a hydraulic pressure in the master cylinder and a hydraulic pressure in the wheel cylinder. A differential pressure control valve for controlling pressure, and control means for controlling an electromagnetic attraction force generated by a solenoid coil in the differential pressure control valve to a force corresponding to the target differential pressure. Brake pressure control device. 13. A wheel cylinder for generating a wheel braking force when braking a vehicle, a master cylinder for applying a hydraulic pressure to the wheel cylinder, a pipe for communicating the wheel cylinder with the master cylinder, and the pipe. And an electromagnetic force that applies an urging force in a direction opposite to the spring force of a spring that constantly applies an urging force to the valve element, an acting force due to a differential pressure between a hydraulic pressure in the master cylinder and an oil pressure in the wheel cylinder. A differential pressure adjusting valve that adjusts the differential pressure between a hydraulic pressure in the master cylinder and a hydraulic pressure in the wheel cylinder according to a relationship between an acting force due to a difference from the suction force and a control unit that controls the electromagnetic suction force And a brake pressure control device for a vehicle, comprising: 14. The control means includes a traveling state detecting means for detecting a traveling state of the vehicle, and a control means for detecting a differential pressure between a hydraulic pressure in the master cylinder and a hydraulic pressure in the wheel cylinder in accordance with the traveling state. 14. The brake pressure control device for a vehicle according to claim 13, wherein a target differential pressure is calculated, and the electromagnetic attraction force is controlled according to the target differential pressure. 15. The method according to claim 1, wherein the amount of energization is a current value to the solenoid coil or a duty ratio when a drive signal to the solenoid coil is a duty signal. A brake pressure control device for a vehicle according to claim 1.