JP2900544B2 - Vehicle brake control device and pressure control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vehicle brake control device that performs brake control by increasing and decreasing the brake oil pressure of a wheel cylinder, and is suitable for performing the brake control. It relates to a pressure control valve.

2. Description of the Related Art Conventionally, in a device for controlling a vehicle such as an anti-skid control device, a three-position valve or a two-port two-position valve is used to switch between increasing, holding, and reducing the brake hydraulic pressure, thereby providing a brake. Adjusting hydraulic pressure. There is also a system in which the brake hydraulic pressure is increased / decreased in a pulsed manner so as to gradually increase / decrease the brake hydraulic pressure (JP-B-51-6308).

[Problems to be Solved by the Invention] However, in the conventional device that adjusts the brake oil pressure by switching the pressure increase, hold, and pressure reduction of the brake oil, the oil pressure phenomenon caused by the switching of the pressure increase, hold, and pressure reduction causes the brake oil pressure to be reduced. There is a problem that a large pulsation is generated, and the vibration is transmitted to the vehicle body via a suspension or the like, thereby generating a large operation sound or vibration, and giving a discomfort to the vehicle driver.

Such an oil hammer phenomenon also occurs on the master cylinder side that generates hydraulic pressure by the operation of the brake pedal by the vehicle driver, and causes the brake pedal to vibrate, so that the vehicle driver may feel uncomfortable from the feet.

Therefore, an object of the present invention is to provide a brake control device or a pressure control valve that suppresses an oil hammer phenomenon caused by a brake hydraulic pressure as much as possible and reduces discomfort to an occupant.

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 is provided in a hydraulic path for supplying oil to a wheel cylinder, and the hydraulic pressure on the wheel cylinder side and the external pressure A first pressure control valve that opens and closes the hydraulic path with a valve body that is displaced in accordance with a pressure set by a command, and controls the oil pressure on the wheel cylinder side to a predetermined pressure in accordance with an external command; The hydraulic path is provided in a hydraulic path for discharging oil from the cylinder, and the hydraulic path is opened and closed by a valve element that is displaced in accordance with a difference between a hydraulic pressure on the wheel cylinder side and a pressure set by an external command, and a hydraulic pressure on the wheel cylinder side. A second pressure control valve that controls the hydraulic pressure controlled by the first pressure control valve to a target pressure when the hydraulic pressure is lower than the target pressure. The oil pressure controlled by the pressure control valve is set to an oil pressure higher than the target pressure. When the oil pressure is higher than the target pressure, the oil pressure controlled by the second pressure control valve is set to the target pressure, and the first pressure control valve is set to the target pressure. And a hydraulic control means for controlling the hydraulic pressure to a target pressure by setting the hydraulic pressure to be controlled to be lower than the target pressure. The invention described in 2 is a pressure control valve that is provided in a hydraulic path from a high pressure side to a low pressure side and continuously controls the low pressure side hydraulic pressure, and is connected to the high pressure side and the low pressure side of the hydraulic path, respectively. A housing having a high-pressure chamber and a low-pressure chamber, a communication hole communicating the high-pressure chamber and the low-pressure chamber, and a hole open to the outside on a side wall surface of the high-pressure chamber facing the communication hole; That opens and closes the low pressure chamber side opening end of the A sliding member comprising: a fitting body slidably fitted in the hole portion; and a connecting body partly inserted into the communication hole to connect the valve body and the fitting body. An urging member for urging the valve body to open the low-pressure chamber-side opening end of the communication hole, and an electromagnetic force generated in accordance with the amount of energization, and the electromagnetic force applies the sliding member to the sliding member. Electromagnetic force generating means for urging the urging member in a direction opposite to the urging force of the urging member, wherein the valve body seals the low-pressure chamber side opening end of the communication hole from the high-pressure chamber side when the valve element is closed. A pressure control valve, wherein a pressure receiving area and a pressure receiving area of a hydraulic pressure received by the fitting body from the high pressure chamber side are set so that the valve body is not displaced by a change in hydraulic pressure of the high pressure chamber. And

Further, the invention according to claim 3 is provided in a hydraulic path for supplying oil to the wheel cylinder, wherein the hydraulic pressure on the wheel cylinder side can be continuously adjusted to a first command pressure according to an externally supplied amount of electricity. (1) a pressure control valve, and a second pressure control valve provided in a hydraulic path for discharging oil from the wheel cylinder and capable of continuously adjusting a hydraulic pressure on the wheel cylinder side to a second command pressure according to an externally supplied amount of electricity. The gist of the invention is a vehicle brake control device, wherein the first command pressure is always set to be smaller than the second command pressure. In the vehicle brake control device according to the above, a target hydraulic pressure applied to the wheel cylinder is calculated,
The energization amount is controlled according to the target oil pressure, and when the target oil pressure increases, the pressure applied to the valve element of the first pressure control valve becomes the target oil pressure, and the valve element of the second pressure control valve When the target oil pressure decreases, the pressure applied to the valve element of the second pressure control valve becomes the target oil pressure, and the pressure applied to the valve body of the second pressure control valve becomes the target oil pressure. The energization control of each of the pressure control valves is performed so that the pressure applied to the valve body of the first pressure control valve is lower than the target oil pressure.

[Operation and Effect of the Invention] As described above, in the vehicle brake control device according to the first aspect, the hydraulic path for supplying oil to the wheel cylinder and the hydraulic path for discharging oil from the wheel cylinder include:
Each hydraulic path is opened and closed by a valve body that is displaced according to the difference between the wheel cylinder side oil pressure and the pressure set by an external command, so that the wheel cylinder side oil pressure can be changed to an external command. First and second control valves for controlling the pressure to a predetermined value are provided. When the oil pressure on the wheel cylinder side is lower than the target pressure, the oil pressure control means sets the oil pressure controlled by the first pressure control valve to the target pressure, and
If the oil pressure controlled by the pressure control valve is set higher than the target pressure, and if the oil pressure on the wheel cylinder side is higher than the target pressure, the oil pressure control means sets the oil pressure controlled by the second pressure control valve to the target oil pressure. The hydraulic pressure controlled by the first pressure control valve is set to a hydraulic pressure lower than the target pressure.

For this reason, when the oil pressure on the wheel cylinder side is lower than the target pressure, the oil pressure of the wheel cylinder is quickly increased to the target pressure by the first pressure control valve without being discharged through the second pressure control valve. On the other hand, when the oil pressure on the wheel cylinder side is higher than the target pressure, the oil pressure is quickly supplied to the target pressure by the second pressure control valve without the oil being supplied to the wheel cylinder via the first pressure control valve. The pressure will be reduced.

Each of the first and second pressure control valves provided in each of the hydraulic paths is a valve that is displaced according to a difference between a hydraulic pressure on a wheel cylinder side to be controlled and a pressure set by an external command. Since each of the hydraulic paths is opened and closed by the body, each hydraulic path is gradually closed as the hydraulic pressure on the wheel cylinder side approaches the target pressure.

Therefore, according to the present invention, even when the hydraulic pressure on the wheel cylinder side is increased through the first pressure control valve or when the hydraulic pressure on the wheel cylinder side is reduced through the second pressure control valve, each hydraulic pressure is set near the target pressure. The hydraulic paths can be closed slowly to prevent pulsation of oil in each hydraulic path. Therefore, according to the present invention, it is possible to prevent the occurrence of the above-described oil hammer phenomenon that gives an uncomfortable feeling to the occupant during the execution of the brake control, and to perform the brake control satisfactorily.

Next, in the pressure control valve according to the second aspect, when the valve body seals the low pressure chamber side opening end of the communication hole, the pressure receiving area of the hydraulic pressure received from the high pressure chamber side, and the fitting body is closer to the high pressure chamber side. Since the pressure receiving area of the received hydraulic pressure is set so that the valve body does not displace due to a change in the hydraulic pressure of the high pressure chamber, the force for biasing the valve body in the direction of opening the low pressure chamber side opening end of the communication hole is biased. It is determined by the biasing force of the member. On the other hand, the force for urging the valve body in the direction of closing the low-pressure chamber side opening end of the communication hole is a value obtained by multiplying the electromagnetic force generated by the electromagnetic force generating means, the pressure receiving area of the valve body and the oil pressure of the low-pressure chamber. Is the sum of

Therefore, according to the pressure control valve of the present invention, the low-pressure side pressure of the hydraulic path can be arbitrarily set by controlling the electromagnetic force generated by the electromagnetic force generating means, that is, the amount of electricity supplied to the electromagnetic force generating means. It becomes possible.

Next, in the vehicle brake control device according to the third aspect, the hydraulic pressure on the wheel cylinder side is supplied to the hydraulic path for supplying oil to the wheel cylinder and the hydraulic path for discharging oil from the wheel cylinder, respectively. The first command pressure that can be continuously adjusted to the first command pressure and the second command pressure according to
A pressure control valve and a second pressure control valve are provided, and the first command pressure is always set smaller than the second command pressure.

For this reason, when the oil pressure on the wheel cylinder side becomes lower than the first command pressure, oil is supplied to the wheel cylinder via the first pressure control valve, and conversely, the oil pressure on the wheel cylinder side becomes lower than the second command pressure. Becomes higher, oil is supplied to the wheel cylinder via the second pressure control valve.

Therefore, in the vehicle brake control device according to the third aspect, the oil pressure on the wheel cylinder side can be maintained within the range from the first command pressure to the second command pressure.
Since the first pressure control valve and the second pressure control valve can continuously change the oil pressure on the wheel cylinder side by changing the amount of energization, the vehicle brake control device according to claim 3 is also provided. In the same manner as in the device according to the first aspect, the oil pressure on the wheel cylinder side can be controlled without generating pulsation in the oil pressure path. It is possible to prevent the occurrence and to perform the brake control satisfactorily.

In the vehicle brake control device according to the third aspect, when the hydraulic pressure on the wheel cylinder side is actually controlled, the target hydraulic pressure to be applied to the wheel cylinder is calculated as described in the fourth aspect. When the energization amount is controlled according to the oil pressure and the target oil pressure increases, the pressure applied to the valve element of the first pressure control valve becomes the target oil pressure, and the pressure applied to the valve element of the second pressure control valve becomes the target oil pressure. When the target oil pressure decreases, the pressure applied to the valve element of the second pressure control valve becomes the target oil pressure and is applied to the valve element of the first pressure control valve. What is necessary is just to comprise so that each pressure control valve may be energized so that pressure may become lower than target oil pressure.

In other words, with this configuration, the target hydraulic pressure increases,
When the oil pressure on the wheel cylinder side becomes lower than the target oil pressure, the first pressure control valve is opened according to the difference between the target oil pressure and the oil pressure on the wheel cylinder side with the second pressure control valve closed. The first pressure control is performed when the hydraulic pressure on the wheel cylinder side is rapidly increased to the target hydraulic pressure while the target hydraulic pressure decreases and the hydraulic pressure on the wheel cylinder side becomes higher than the target hydraulic pressure. With the valve closed, the second pressure control valve is opened according to the difference between the target oil pressure and the oil pressure on the wheel cylinder side, and the oil pressure on the wheel cylinder side is immediately reduced to the target oil pressure. .

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an anti-skid control device according to an embodiment to which the present invention is applied. FIG. 1 shows a configuration of a control system of only one wheel of the anti-skid control device for the sake of simplicity of description.
It is well-known that it is provided for each wheel of the vehicle.

As shown in the drawing, in the anti-skid control device of the present embodiment, a high pressure connecting a master cylinder 4 for generating a hydraulic pressure in accordance with the depression amount of the brake pedal 2 and a wheel cylinder 8 for applying a braking force to the wheels 6 is provided. Side hydraulic piping
Pressure control valves 16 and 18 for controlling the oil pressure on the wheel cylinder 8 side are provided on the low-pressure-side hydraulic pipe 14 connecting the wheel cylinder 8 and the reservoir 12, respectively. Further, the pump 20 can supply the high-pressure oil pumped from the reservoir 12 to the upstream side of the pressure control valve 16 of the high-pressure hydraulic pressure pipe 10.

Next, the drive of the pump 20 and the pressure control valves 16 and 18 is controlled by an electronic control circuit (hereinafter simply referred to as ECU) 22. E
CU 22 is a wheel speed sensor 24 for detecting the rotation speed of the wheel 6.
Also, based on a detection signal from a wheel speed sensor (not shown) that detects the rotation speed of other wheels of the vehicle, a slip state of the wheels 6 during vehicle braking is detected.
The CPU 20 controls the brake oil pressure of the wheel cylinder 8 by driving the pump 20 and the pressure control valves 16 and 18 to execute anti-skid control described below for optimally braking without locking the wheels 6. It is composed of a well-known microcomputer composed of ROM, RAM and the like.

Next, a pressure control valve 16 provided in the hydraulic pipe 10 on the high pressure side
Are configured as shown in FIG.

As shown in the figure, the pressure control valve 16 has two large and small cylinders 30, 3
A cylindrical housing 33 comprising a coil 32 as an electromagnetic force generating means provided between 1 and the cylindrical bodies 30 and 31; and a cylindrical housing
An inner housing 34 for closing the hollow portion 33 from below, and an outer housing further provided below the inner housing 34
35, an inner housing 37 forming a low-pressure chamber 36 between the inner housing 34 by closing the hollow portion of the cylindrical housing 33 from above, and an outer housing 38 further provided above the inner housing 37. A formed housing.

Next, in the center of the inner housing 37, a communication hole 39 communicating with the low-pressure chamber 36, and a hollow portion 41 which is larger in diameter than the communication hole 39 and forms a high-pressure chamber 40 with the outer housing 38 are formed. A hole 42 open to the atmosphere is formed at a position of the outer housing 38 facing each of these parts. Low pressure chamber 36
Is connected to the hydraulic pipe 10 on the wheel cylinder 8 side through hydraulic pressures 34a and 35a formed in the inner housing 34 and the outer housing 35, respectively.
It is connected to a hydraulic pipe 10 on the master cylinder 4 side via an oil passage 38a formed in 38.

On the other hand, the low-pressure chamber 36 is provided with an armature 44 that is urged upward by an electromagnetic force generated when the coil 32 is energized.The upper center of the armature 44 has an opening end of the communication hole 39 in accordance with the movement of the armature 44. A ball 46 is provided as a valve that opens and closes. A plunger 47 as a fitting body is slidably fitted in the hole 42 of the outer housing 38, and a spring 48 as a biasing member for biasing the plunger 47 toward the low-pressure chamber 36 is provided. I have. And plunger
A rod 49 connected to 47 is in contact with a ball 46 fixed to the armature 44. A conical seat portion 50 is formed at the opening end of the communication hole 39 with which the ball 46 comes into contact by the upward movement of the armature 44 so that the ball 46 is firmly seated.

In FIG. 2, reference numerals 51 to 54 denote O-rings for preventing oil from leaking from the high-pressure chamber 40 or the low-pressure chamber 36. In the present embodiment, as shown in FIG.
The pressure receiving area S1 of the high-pressure oil received from the high pressure oil S4 and the pressure receiving area S2 of the high-pressure oil received by the ball 46 from the high-pressure chamber 40 when the ball 46 is seated on the seat portion 50 are made to match.

In the pressure control valve 16 configured as described above, even if the hydraulic pressure of the high pressure chamber 40 that receives the pressure oil from the master cylinder 4 or the pump 20 changes, the force for urging the ball 46 downward does not change. It is determined only by the biasing force FSP by the spring 48. On the other hand, assuming that the electromagnetic force generated by the coil 32 when energized is FE and the oil pressure of the wheel cylinder 8 is PW / C, FE + PW / C · S2 (where S2: ball 46
Pressure receiving area).

Therefore, the hydraulic pressure PW / C of the wheel cylinder 8 is given by PW / C = (FSP-FE) / S2... Since S2 and FSP are constant, as shown in FIG.
The hydraulic pressure PW / C of the wheel cylinder 8 changes according to the electromagnetic force FE generated by the coil 32. According to the pressure control valve 16 of the present embodiment, by controlling the current supplied to the coil 32, The hydraulic pressure of the cylinder 8 can be controlled.

In the present embodiment, the spring constant of the spring 48 is set to be larger than the change rate of the electromagnetic force with respect to the stroke of the armature 44, and as the oil pressure of the wheel cylinder 8 approaches the target pressure, the ball 46 Approaching the ball
Since the oil passage formed between 46 and seat portion 50 is gradually narrowed, as shown in FIG. 5, even if the current supplied to coil 32 is changed stepwise at time t0, wheel cylinder 8 The oil pressure changes smoothly, and no oil hammer occurs.

On the other hand, a pressure control valve 18 provided in the low pressure side hydraulic pipe 14
As shown in FIG. 5, the oil chamber 63 is connected to the hydraulic cylinder 14 via the communication hole 61 on the wheel cylinder 8 side, and is connected to the hydraulic pipe 14 via the communication hole 62 on the reservoir 12 side. Room 63
Armature 65 provided with a ball 64 for opening and closing the open end of the communication hole 61 on the wheel cylinder 8 side, a spring 66 for urging the armature 65 toward the communication hole 61, and a spring 66 for urging the armature 65 by electromagnetic force. And a coil 67 for urging in a direction opposite to the urging force.

In the pressure control valve 18 configured as described above, the oil chamber
63 communicates with reservoir 12 so that ball 64 communicates with communication hole
The force urging the opening end side of 61 is the urging force FSA by the spring 66, and the force urging the ball 64 in the direction away from the opening end of the communication hole 61 is the electromagnetic force generated by the coil 67 by energizing FE1. , PW / C hydraulic pressure of wheel cylinder 8, ball 64
The pressure receiving area when S is in contact with the open end of the communication hole 61 is S3
Then, FE1 + PW / C · S3 is obtained.

Accordingly, the hydraulic pressure PW / C of the wheel cylinder 8 becomes PW / C = (FSA-FE1) / S3..., And controls the current supplied to the coil 67 similarly to the pressure control valve 16 provided in the high-pressure hydraulic pressure pipe 10. This makes it possible to control the oil pressure of the wheel cylinder 8.

Next, an anti-skid control process executed by the ECU 22 as the pressure control means will be described with reference to the flowchart of FIG. This process is executed by the ECU 22 at predetermined intervals.

As shown in the figure, in the anti-skid control process, first, in step 200, a wheel speed Vw is calculated based on a signal from the wheel speed sensor 24, and in subsequent step 210,
The wheel acceleration αw is calculated. Next, at step 220, the estimated vehicle speed Vb and its acceleration αb are calculated based on signals from the wheel speed sensor 24 and other wheel speed sensors (not shown). In the following step 230, a reference speed Vs for determining a wheel lock tendency is created based on the estimated vehicle speed Vb obtained in step 220. That is, the estimated vehicle speed Vb
(For example, 0.7 to 0.95), a speed corresponding to a target slip ratio is obtained, and a value obtained by subtracting the offset speed Vo from the speed is calculated as a reference speed Vs as in the following equation.

Vs = Ko · Vb−Vo… The offset speed Vo is subtracted from Ko · Vb even when the estimated vehicle speed Vb decreases, the speed difference between the estimated vehicle speed Vb and the reference speed Vs being larger than the offset speed Vo. It is to have.

Next, in step 240, based on the estimated vehicle body acceleration αb and the reference speed Vs obtained in steps 220 and 230, a parameter W (hereinafter, referred to as a wheel parameter) W representing the locking tendency of the wheel 6 is calculated by the following equation. .

W = A · (Vw−Vs) + B · (αw−αb) where A and B are positive constants, and a wheel parameter W formed by this equation is a wheel parameter when W ≧ 0. 6
Means that there is no lock tendency, and W <0 means that there is a lock tendency, and the absolute value of W indicates the strength of the lock tendency.

Then, in the subsequent step 250, it is determined whether or not the brake hydraulic pressure is currently controlled, that is, whether or not the anti-skid control is actually started. If the control is started, the process proceeds to step 280, and the control is started. Step 2 if done
Move to 60.

In step 260, the locking tendency of the wheel 6 is determined by comparing the wheel parameter W obtained in step 240 with the control start level -Kw (where Kw is a positive constant), and W <-
If Kw, the process proceeds to step 270 to drive the pump 20 (O
N) to start the anti-skid control, and proceed to step 280. Conversely, if W ≧ −Kw, it is determined that the wheels 6 do not have a locking tendency, and the process is temporarily terminated.

In step 280, it is determined whether or not the state where the wheel parameter W becomes 0 or more continues for Te seconds (for example, 0.5 to 2 seconds). If an affirmative determination is made in step 280, it is determined that the locking tendency of the wheel 6 has been completely suppressed, and the flow shifts to step 290, where the pump 20 is turned off (OFF) and the pressure applied during the control is reduced. The control is terminated by stopping the energization of the control valves 16 and 18.

On the other hand, if a negative determination is made in step 280, it is determined that the lock of the wheel 6 has not been completely suppressed, and the process proceeds to step 300, where the target hydraulic pressure Po of the wheel cylinder 8 is calculated based on the wheel parameter W. Note that the target hydraulic pressure Po is
For example, the calculation can be performed by first multiplying the positive constant K1 by the wheel parameter W to obtain the target oil pressure change amount δP, and adding this to the previously obtained target oil pressure Po (n-1). In executing this calculation, the absolute value of the wheel parameter W is compared with a predetermined value A. When the absolute value of the wheel parameter W is smaller than the predetermined value A, the value of the wheel parameter W is set to zero, When the absolute value of W is larger than the predetermined value A, the wheel parameter set in such a procedure that the value of the wheel parameter W is left as it is is used.

Then, in step 310, the target hydraulic pressure Po
Is increased, decreased, or equal to the previous target oil pressure Po (n-1), and the target oil pressure Po is increased, that is, the oil pressure of the wheel cylinder 8 is increased. In step 320, the target oil pressure PA of the pressure control valve 16 and the target oil pressure PB of the pressure control valve 18 are set as in the following equations.

PA = Po, PB = PA + ΔP (where ΔP is a constant value) On the other hand, if the target oil pressure Po is increasing, that is, if the oil pressure of the wheel cylinder 8 is to be reduced, at step 330, the pressure control valve 18 The target oil pressure PB and the target oil pressure PA of the pressure control valve 16 are set as follows, respectively. PB = Po, PA = PB-ΔP When the target oil pressure Po is not changed, that is, the oil pressure of the wheel cylinder 8 is changed. If you want to keep, in step 340
The previously determined values are set as the target oil pressure PA of the pressure control valve 16 and the target oil pressure PB of the pressure control valve 18.

When the target oil pressure PA of the pressure control valve 16 and the target oil pressure PB of the pressure control valve 18 are set as described above, the process proceeds to the subsequent step 350, where the energizing current to each of the pressure control valves 16, 18 is obtained. A drive signal for controlling to a current value corresponding to the set target oil pressures PA and PB is output.

The target oil pressures PA and PB of the pressure control valves 16 and 18 are set as described above because the oil pressure can be changed without delay by changing PA and PB at the time of switching between pressure increase and pressure reduction. However, the pressure control valve 18 during pressure increase shown in the above equation
An upper limit value is set for the target oil pressure PB, and the hydraulic pipe 14 is fully closed. Conversely, a lower limit value is set for the target oil pressure PA of the pressure control valve 16 at the time of pressure reduction shown in the above equation. Alternatively, the hydraulic pipe 10 may be completely closed.

As described above, in the anti-skid control device of the present embodiment, the high-pressure side hydraulic pipe 10 for supplying oil pressure to the wheel cylinder 8 and the low-pressure side hydraulic pipe 14 for discharging oil from the wheel cylinder 8 are provided with: Since the pressure control valves 16 and 18 are provided, respectively, the hydraulic pressure of the wheel cylinder 8 can be controlled to a desired value, and the braking force of the vehicle can be optimally controlled. Each pressure control valve 16, 18 is
As the pressure difference between the oil pressure of the wheel cylinder 8 and the target oil pressure becomes smaller, the flow area of the oil is reduced, so that the oil hammer phenomenon that occurs when the control is executed can be suppressed. I do not receive.

Next, another configuration example of the pressure control valve 16 provided in the high-pressure side hydraulic pipe 10 that supplies oil to the wheel cylinder 8 will be described with reference to FIGS. 8 and 9. 8 and 9, the same components as those of the pressure control valve 16 of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

First, the pressure control valve 70 of FIG. 8 reduces the sliding resistance of the plunger 47 by removing the O-ring 51 provided between the plunger 47 and the hole 42 in the pressure control valve 16 of the above embodiment. Things. If the O-ring 51 is simply removed, oil in the high-pressure chamber 40 leaks to the outside through the sliding surface of the plunger 47. When energized, the ball 72 contacts the partition wall 74 to isolate the plunger 47 from the high-pressure chamber 40.
Are provided, respectively, to prevent the oil from leaking to the outside at the time of the normal braking in which the brake control is not executed, thereby preventing the braking force from being reduced. When using this pressure control valve 70,
When the brake is controlled by energizing the coil 32, the oil leaks from the hole 42 of the outer housing 38, and therefore, it is desirable that the hole 42 communicates with the reservoir 12.

Next, the pressure control valve 80 of FIG. 9 separates the plunger 47 and the rod 49 of the above embodiment and provides a spring 82 between them. The pressure receiving area of the ball 46 is Sa, the plunger is
When the pressure receiving area of 47 is Sb, and the spring constants of the springs 82 and 48 are Ka and Kb, respectively, the following formula is established.

Kb / Ka = (Sb−Sa) / Sa That is, when the coil 32 is energized and the ball 46 is seated on the seat portion 50, the force Fa for urging the armature 44 toward the seat portion 50 is a high pressure chamber. If the oil pressure of 40 is PM / C and the spring force of the spring 82 is FSP1, Fa = PM / C.Sa + FSP1... If the spring force of the spring 82 when PM / C = Po is FSP10, then Fa = Po.Sa + FSP10... The spring force FSP2 of the spring 48 is as follows: FSP2 = Po · Sb + FSP10

Here, the spring force of the spring 48 when PM / C = P1 is FSP
Assuming that the plunger 47 is displaced by x, the following equation is satisfied. By substituting the equation into the equation and further substituting the equation, P1 · Sa−Ka · x = Po · Sa is obtained. By substituting this equation into the equation, the above equation is obtained. That is, Fa is constant regardless of the value of PM / C.

Accordingly, it can be seen that the hydraulic pressure of the wheel cylinder 8 can be controlled by controlling the current supplied to the coil 32 also in the pressure control valve 80, similarly to the pressure control valve 16 in the above embodiment.

Here, in the above description, each of the pressure control valves 16, 18, 7
0,80, it is described that the hydraulic pressure of the wheel cylinder 8 can be controlled by controlling the current supplied to the coils 32,67. However, when the respective pressure control valves 16,18,70,80 are actually driven, the current It is not necessary to perform the control, and the hydraulic pressure of the wheel cylinder 8 can also be controlled by so-called duty control for controlling the energized / deenergized time of the coils 32 and 67.

In the above embodiment, the brake hydraulic pressure control system includes:
The control system of the reflux type in which the oil flows back from the reservoir 12 → the pump 20 → the pressure control valve 16 → the wheel cylinder 8 → the pressure control valve 18 → the reservoir 12 has been described as an example. The present invention can be applied to such cases.

Further, in the above-described embodiment, the anti-skid control device has been described. However, the present invention is not limited to the anti-skid control device. For example, a traction control device that controls acceleration hydraulic slip of the vehicle by controlling brake hydraulic pressure during vehicle acceleration, Any control system that performs brake control can be applied.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an anti-skid control device according to an embodiment to which the present invention is applied, FIG. 2 is a cross-sectional view showing a configuration of a pressure control valve provided in a high-pressure side hydraulic pipe, and FIG. Is an explanatory diagram for explaining the pressure receiving area of the plunger and the ball of the pressure control valve, FIG. 4 is a diagram for explaining the characteristics of the pressure control valve, FIG. 5 is a time chart for explaining the operation of the pressure control valve, FIG. 6 is a sectional view showing the configuration of a pressure control valve provided in the low-pressure side hydraulic pipe, FIG. 7 is a flowchart showing anti-skid control processing executed by the ECU, and FIGS. It is a sectional view showing other examples of composition of a pressure control valve provided in a side hydraulic piping. 4 Master cylinder, 8 Wheel cylinder 10, 14 Hydraulic piping, 12 Reservoir 16, 18 Pressure control valve, 32 Coil 33 Cylindrical housing 34, 37 Inner housing 35 38, external housing, 36, low pressure chamber, 39, communication hole, 40, high pressure chamber, 41, hollow part 42, hole, 44, armature, 46, ball 47, plunger, 48… Spring 49… Rod, 50… Seat

Continuation of the front page (72) Inventor Hideki Inoka 1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-56-2244 (JP, A) JP-A-56-79044 (JP) , A) (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 8/34-8/86 F16K 31/06

Claims (4)

(57) [Claims] An oil pressure path for supplying oil to a wheel cylinder opens and closes the oil pressure path with a valve element that is displaced in accordance with a difference between oil pressure on the wheel cylinder side and pressure set by an external command. A first pressure control valve for controlling the oil pressure on the wheel cylinder side to a predetermined pressure in accordance with an external command, and a hydraulic pressure path for discharging oil from the wheel cylinder. A second pressure control valve that opens and closes the hydraulic path with a valve body that is displaced in accordance with a set pressure and controls the hydraulic pressure on the wheel cylinder side to a predetermined pressure according to an external command; When the pressure is lower than the target pressure, the oil pressure controlled by the first pressure control valve is set to the target pressure, and the oil pressure controlled by the second pressure control valve is set to a higher oil pressure than the target pressure. In this case, the hydraulic pressure controlled by the second pressure control valve is set to a target pressure, and the hydraulic pressure controlled by the first pressure control valve is set to a lower pressure than the target pressure, thereby controlling the hydraulic pressure to the target pressure. A vehicle brake control device comprising: a hydraulic control unit. 2. A pressure control valve provided in a hydraulic path from a high pressure side to a low pressure side for continuously controlling the hydraulic pressure on the low pressure side, the high pressure valve being connected to the high pressure side and the low pressure side of the hydraulic path, respectively. A housing having a chamber and a low-pressure chamber, a communication hole communicating the high-pressure chamber and the low-pressure chamber, and a hole open to the outside on a side wall surface of the high-pressure chamber facing the communication hole; A valve body that opens and closes the chamber-side open end, a fitting body slidably fitted in the hole, and a connecting body that is partially inserted into the communication hole and connects the valve body and the fitting body; A sliding member comprising: a biasing member for biasing the sliding member in a direction in which the valve body opens the low-pressure-chamber-side opening end of the communication hole; Electromagnetic force generating means for urging the sliding member in a direction opposite to the urging force of the urging member by this electromagnetic force, And the pressure receiving area of the hydraulic pressure received from the high pressure chamber side when the valve body seals the low pressure chamber side opening end of the communication hole, and the pressure receiving area of the hydraulic pressure received by the fitting body from the high pressure chamber side. Is set so that the valve body is not displaced by a change in oil pressure in the high-pressure chamber. A first pressure control valve provided in a hydraulic path for supplying oil to the wheel cylinder, wherein the first pressure control valve is capable of continuously adjusting a hydraulic pressure on the wheel cylinder side to a first command pressure according to an externally supplied amount of electricity; A second pressure control valve provided on a hydraulic path for discharging oil from the wheel cylinder, the second pressure control valve being capable of continuously adjusting a hydraulic pressure on the wheel cylinder side to a second command pressure according to an externally supplied amount of electricity; The first command pressure is always set to be smaller than the second command pressure. 4. A brake control apparatus for a vehicle according to claim 3, wherein a target hydraulic pressure applied to said wheel cylinder is calculated, said energization amount is controlled according to said target hydraulic pressure, and said target hydraulic pressure is increased. Controlling the energization of each of the pressure control valves so that the pressure applied to the valve element of the first pressure control valve becomes the target oil pressure and the pressure applied to the valve element of the second pressure control valve becomes higher than the target oil pressure. When the target oil pressure decreases, the pressure applied to the valve element of the second pressure control valve becomes the target oil pressure, and the pressure applied to the valve element of the first pressure control valve becomes lower than the target oil pressure. A brake control device for a vehicle, wherein the pressure control valves are energized.