JPH10203342A - Anti-skid control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure good brake pedal feeling even in low speed running region and provide an anti-slid control device that does not give a feeling of physical disorder to the driver. SOLUTION: When car body speed VB is larger than KVB1, enabling anti- skid control, anti-skid is controlled to the slip ratio that provides the largest braking force by increasing or decreasing the brake pressure of the front and rear wheels so that their brake pressure becomes same as each other. At this moment, the pedal stroke increases with an increase in pressure. When VB <=KLVB1 at a time point t1, the brake pressure applied to the front wheels is made to increase by stages according to a specified pattern, the brake pressure applied to the rear wheels holds the current value. For this reason, even if the brake pressure applied to the front wheels is continuously increased, an increase in the pedal stroke made half, not giving a feeling of uncomfortableness to the driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid control device for adjusting a wheel slip generated when a vehicle is braked, and more particularly, to an anti-skid control for increasing a brake pressure by using a fluid pressure generated by a master cylinder. Related to the device.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, a slip state detecting means for detecting a slip state of a wheel at the time of braking of a vehicle, a master cylinder for generating a fluid pressure in response to operation of a brake pedal, Brake pressure adjusting means for increasing and decreasing the brake pressure of the wheels so that the slip state detected by the means becomes an appropriate state. The brake pressure adjusting means adjusts the fluid pressure generated by the master cylinder. An anti-skid control device for increasing the brake pressure by using the anti-skid control device has been considered.

In this anti-skid control device, at the time of braking of the vehicle, the brake pressure adjusting means increases and decreases the brake pressure of the wheels so that the slip state detected by the slip state detecting means becomes an appropriate state. . Therefore, the occurrence of skid can be prevented, and the braking distance can be shortened favorably. However, it is difficult to detect a slip state in a low-speed traveling region. Therefore, in this type of device,
When the vehicle speed falls below a predetermined speed, the control is terminated, and the fluid (for example, brake fluid) flowing out of the master cylinder is directly supplied to the brake device or the like.

[0004]

However, in the above device, since the brake pressure adjusting means increases the brake pressure using the fluid pressure generated by the master cylinder, the movement of the brake pedal is restricted during the control. . At the time of control termination, the fluid flowing out of the master cylinder is supplied as it is as described above. For this reason,
The brake pedal suddenly becomes lighter as soon as the control is terminated. In this case, a braking operation feeling in a low-speed traveling region, that is, a so-called brake pedal feeling is deteriorated, and the driver may feel uncomfortable.

Accordingly, an object of the present invention is to provide an anti-skid control device which ensures a good brake pedal feeling even in a low-speed running region and does not give a driver an uncomfortable feeling.

[0006]

According to a first aspect of the present invention, there is provided an anti-skid control device for increasing a brake pressure by using a fluid pressure generated by a master cylinder. When the brake pressure adjusting means reduces the vehicle speed to a predetermined speed or less due to braking,
By increasing the brake pressures of the plurality of wheels at different timings, a temporal change in the fluid outflow amount from the master cylinder is suppressed.

In the present invention having the above-described structure, when the vehicle speed falls below a predetermined speed due to braking, the brake pressure adjusting means increases the brake pressure of the plurality of wheels at different timings. For this reason, the fluid for increasing the brake pressure of each wheel flows out of the master cylinder at different timings, and it is possible to suppress a temporal change in the fluid outflow amount. In other words, the temporal change of the fluid outflow amount is moderated by the number of wheels, and becomes gentle. Therefore, according to the present invention, the brake pedal feeling does not deteriorate even in the low-speed traveling region, and the driver does not feel uncomfortable.

According to a second aspect of the present invention, there is provided an anti-skid control device for increasing a brake pressure by using a fluid pressure generated by a master cylinder, wherein the brake pressure adjusting means is provided when the vehicle speed falls below a predetermined speed due to braking. The brake pressure is increased or decreased so that the fluid outflow amount from the master cylinder has a value corresponding to the outflow amount until the vehicle speed falls below the predetermined speed.

According to the present invention having the above-described structure, when the vehicle speed becomes equal to or lower than the predetermined speed due to the braking, the brake pressure adjusting means adjusts the amount of fluid outflow from the master cylinder until the vehicle speed becomes equal to or lower than the predetermined speed. The brake pressure is increased and decreased so as to have a value corresponding to. For this reason, the fluid outflow amount from the master cylinder becomes a value corresponding to each other before and after the vehicle speed becomes equal to or lower than the predetermined speed, and the temporal change thereof can be suppressed. Therefore, in the present invention, the brake pedal feeling does not deteriorate even in the low-speed traveling region,
Does not give the driver a sense of incompatibility.

[0010] The third aspect of the present invention is the first or second aspect.
In addition to the configuration described above, the brake pressure adjusting means does not have a pressure source of the brake pressure other than the master cylinder,
The brake pressure is increased by supplying the fluid flowing out of the master cylinder as it is, and the brake pressure is reduced or maintained by inhibiting the fluid from flowing out of the master cylinder.

According to the present invention, the brake pressure is increased by directly supplying the fluid flowing out of the master cylinder, and the brake pressure is reduced or maintained by inhibiting the fluid from flowing out of the master cylinder. Therefore, the operation of the brake pressure adjusting means is directly reflected on the brake pedal feeling. Also, in an anti-skid control device having a brake pressure source other than the master cylinder, a phenomenon in which the brake pedal is pushed back during the braking operation (so-called kickback) occurs, and even if the brake pedal feeling changes, the user feels too uncomfortable. , But kickback does not occur in the anti-skid control device having no other pressure source. For this reason, the user feels particularly uncomfortable with the change in the brake pedal feeling, and there is a strong demand for preventing the brake pedal feeling from deteriorating.

According to the present invention, there is provided an anti-skid control device having no pressure source other than the master cylinder.
Since the deterioration of the brake pedal feeling can be prevented similarly to the invention of the second aspect, the above-mentioned effect of the first or second aspect of the invention becomes more remarkable.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of an anti-skid control device to which the present invention is applied. As shown in FIG. 1, an electromagnetic pickup type or magnetoresistive element (MRE) type wheel speed sensor 5 to 8 is disposed on each of the right front wheel 1, the left front wheel 2, the right rear wheel 3, and the left rear wheel 4. And
A pulse signal is generated according to the rotation of each of the wheels 1-4.

On each of the wheels 1 to 4, hydraulic brake devices (wheel cylinders) 11 to 14 are provided, respectively, and hydraulic pressure from the master cylinder 16 is applied to the actuators 21 to 2 respectively.
4 and each wheel cylinder 11 through each hydraulic line
14 is sent. The master cylinder 16 is a well-known type that generates a hydraulic pressure when the brake pedal 27 is depressed, and the depressed state of the brake pedal 27 is detected by a stop switch 29.

The wheel cylinders 11 and 14 are connected to a reservoir 37 via actuators 31 and 34, and the wheel cylinders 12 and 13 are connected to a reservoir 39 via actuators 32 and 33, respectively. In addition,
Each of the actuators 21 to 24 and 31 to 34 is an electromagnetic two-position valve having a communicating position and a blocking position.

A bypass pipe is provided upstream and downstream of the actuators 21 to 24 so that only pressure oil flowing from the wheel cylinders 11 to 14 to the master cylinder 16 is circulated around the actuators 21 to 24 by check valves 41 a to 44 a. Roads 41 to 44 are provided. Further, the reservoirs 37, 39 and the master cylinder 16 are connected to the check valves 47,
49, and is connected to the reservoir 3
Only the flow of pressure oil from 7, 39 to the master cylinder 16 is permitted.

The detection signals from the wheel speed sensors 5 to 8 and the stop switch 29 are input to an electronic control circuit (ECU) 50. The electronic control circuit 50 includes a CPU, RO
A well-known microcomputer having M, RAM, and I / O circuits.
1 to 24 and 31 to 34.
This control signal is composed of a pressure increase output, a hold output, and a pressure decrease output generated for each of the wheels 1 to 4. Here, the operation of the actuators 21 to 24 and 31 to 34 corresponding to each output will be described by taking the right front wheel 1 as an example.

To generate an increased pressure output at the right front wheel 1 means to generate a control signal so that the actuator 21 is disposed at the communication position and the actuator 31 is disposed at the cutoff position. Then, the hydraulic pressure generated by the master cylinder 16 is supplied to the wheel cylinder 11 as it is.

To generate the holding output at the right front wheel 1 means to generate a control signal so that both the actuators 21 and 31 are disposed at the shut-off position. Then, the hydraulic pressure of the wheel cylinder 11 is maintained. If the brake pedal 27 is released during the continuation of the hold output, the pressure oil flows through the bypass pipe 41 and the oil pressure of the wheel cylinder 11 is reduced.

To generate a decompression output to the right front wheel 1 means to generate a control signal so that the actuator 21 is disposed at the cut-off position and the actuator 31 is disposed at the communication position. Then, the pressure oil of the wheel cylinder 11 flows into the reservoir 37, and the oil pressure is reduced. Note that the electronic control circuit 50 performs the same output for the other wheels 2 to 4.

Next, the processing executed by the electronic control circuit 50 will be described in detail with reference to the flowcharts of FIGS.
When the ignition key is turned on, the electronic control circuit 50 executes a main routine shown in FIG. The electronic control circuit 50 executes this main routine for each of the wheels 1 to 4 in a time-sharing manner.

When the process is started, first, in step 100, an initialization process is executed. In this initialization process, the RAM
The processing of clearing the contents of various variables and counters and resetting flags is performed. Subsequently, the process waits until a predetermined time Tams (for example, 5 ms) has elapsed from the previous processing (step 110), and when the predetermined time Tams has elapsed (110: YES), the process proceeds to the subsequent step 120.

In step 120, the wheel speed sensor (5
8), the wheel speed VW of the wheel to be controlled is calculated, and in step 130, the wheel speed VW is differentiated with respect to time to calculate the wheel acceleration dVW. Subsequently, when the process proceeds to step 140, the wheel speed V calculated in step 120 for each of the wheels 1-4.
Based on W, the vehicle speed VB (estimated vehicle speed) is calculated as follows. That is, the wheel speed V of each wheel 1-4
The maximum wheel speed VW of W, the vehicle speed VB calculated by the previous process (set to 0 during the initialization process), the upper limit of the vehicle acceleration that can be taken in the actual vehicle running state, and the vehicle deceleration An intermediate value of the upper and lower limit speeds in consideration of the upper limit of (negative acceleration) is defined as the vehicle speed VB.

In the following step 150, step 140
The vehicle speed VB calculated in the above is differentiated with respect to time to obtain the vehicle speed d.
VB is calculated, and in the following step 160, the wheel slip ratio S is calculated based on the wheel speed VW and the vehicle speed VB.
After calculating W, the process proceeds to step 170.

In step 170, a control mode calculation process shown in FIGS. As shown in FIGS. 3 and 4, when the process is started, it is determined in step 200 whether or not the brake pedal 27 is operated and the stop switch 29 is turned on. Stop switch 29 is off
In other words, when the vehicle is not braking, (20
(0: NO), the process proceeds to step 202 to reset a control mode, which will be described later, and then sets the pressure increase mode (204), and then returns to the main routine. Then, Figure 2
As shown in FIG.
Then, after the predetermined time Tams has elapsed again, the above processing is repeated. The pressure increase mode is a mode in which the above-described pressure increase output is continuously generated. That is, when the vehicle is not being braked (200: NO), the master cylinder 1
6 generates the wheel cylinders 11 to 1
4.

When the brake pedal 27 is operated and the stop switch 29 is turned on (200: YES), the routine proceeds to step 210, where it is determined whether or not the control mode is set. At the start of braking, since the control-in-progress mode has been reset in step 202, a negative determination is made and the process proceeds to step 212. In step 212, the vehicle speed VB is set to the predetermined speed K which requires the anti-skid control.
It is determined whether or not it is higher than VB0 (for example, 8 km / h). Step 21
At 4, the slip ratio SW is set to a predetermined value KS0 (for example, 20).
%) Is determined. Immediately after the start of braking, almost no slippage has occurred, so a negative determination is made and the process proceeds to steps 202 and 204 described above to set the pressure increase mode. In step 212, VB ≦ KVB0 (NO)
When the determination is made, the process similarly proceeds to steps 202 and 204.

By continuing braking in the pressure increasing mode, the slip ratio SW increases, and when SW> KS0 (214:
YES), the process proceeds to step 220, and the control mode is set. In the following step 222, the vehicle speed VB is set to a lower limit KVB1 (for example, 4 km) at which anti-skid control is possible.
/ h) is determined, and a positive affirmative determination is made at the beginning of braking, and the routine proceeds to step 224. In step 224, it is determined whether the slip ratio SW is larger than a predetermined value KS1 (for example, 15%). If this is the first time, the routine proceeds to step 226 with an affirmative determination. In step 226, it is determined whether or not the wheel acceleration dVW is equal to or less than 0G and the wheel is being locked. dVW
If ≤0G (226: YES), after setting the decompression mode in step 228, if dVW> 0G (22
(6: NO) returns to the main routine after setting the holding mode in step 230.

Here, the depressurization mode is a mode in which the above-described holding output and the depressurizing output are alternately and repeatedly generated (for example, by switching every 15 ms), and the holding mode continuously generates the above-described holding output. Mode. That is,
If dVW ≦ 0 G and the wheels are being locked (226: YES), the oil pressure (brake pressure) of the wheel cylinders 11 to 14 is gradually reduced by the pressure reduction mode, and d
If VW> 0G and the slip is gradually being eliminated (226: NO), the brake pressure is held in the holding mode. If the process returns to step 210 again after the above process, the control-in-progress mode has already been set (220), and the process directly proceeds from step 210 to step 220 and subsequent processes.

Whether the slip ratio SW becomes KS1 or less by repeating the above processing (224: NO), or
If the vehicle speed VB becomes equal to or less than KVB1 (222:
NO) Go to step 232. Here, it is determined whether or not the pulse increase pattern has been completed. At first, a negative determination is made and the process proceeds to step 234. Here, the pulse increase mode calculation processing shown in FIG. 5 is executed.

As shown in FIG. 5, when this process is started, it is first determined at step 300 whether or not VB> KVB1. If VB> KVB1 (300: YES), the flow shifts to step 320, where the pattern A in the pulse increasing mode is set, and the flow returns to the main routine. Here, the pulse increasing mode is a mode in which the above-described holding output and the pressure increasing output are alternately and repeatedly generated as illustrated in FIG.
This mode has three patterns A, B, and C. For each pattern, the duration KH of the holding output, the duration KU of the boosted output, and the number of pulses N
Are set as shown in Table 1.

[0031]

[Table 1]

When the pattern A is set in step 320, the holding output (100 ms) and the pressure increasing output (3 ms) are repeated according to this pattern (five times). During execution of the pulse increasing mode, the slip ratio SW increases and SW> KS1
Is satisfied (step 224: YES), the pressure reduction mode (228) or the holding mode (230) is set as described above to eliminate the slip. When the pulse increase mode ends, the determination in step 232 is affirmative, and the process proceeds to step 20.
The routine proceeds to step 2204, where the control mode is reset and the pressure increase mode is set.

If VB ≦ KVB1 (222: NO) and the process proceeds to step 234, a negative determination is made in step 300 and the process proceeds to step 340. Step 34
0, the value of the counter memory CM described below is set to a predetermined value K
Compared with M, if CM <KM (340: YES), the B pattern of the pulse increase mode is set in step 360, and if CM ≧ KM (340: NO), the pulse increase mode is set in step 380. After setting the C pattern, the process returns to the main routine.

FIG. 6 is a flowchart showing a pedal entry estimation routine executed in a routine different from the above processing. This process is a process for setting the value of the counter memory CM, and the electronic control circuit 50 repeatedly executes this process at predetermined time intervals. Further, the counter memory CM
The value corresponds to the entry speed of the brake pedal 27 as follows.

When the process is started, it is first determined at step 400 whether or not the ABS control is being performed. Here, ABS control is in a state where the above-described control mode is set. If the ABS control is not being performed (400: NO), the process proceeds to step 402, where the counter memory CM, the total pressure increase output time counter CL, and the gate time counter CT are set to 0.
And the process ends once.

If the ABS control is being performed (400: YES), the flow shifts to step 404 to determine whether or not the gate time counter CT has reached a predetermined value KT. Initially, CT = 0, so a negative determination is made and the process proceeds to step 406. In step 406, the value of the gate time counter CT is incremented by one, and in step 410, the right front wheel 1
It is determined whether or not the pressure increase output has been made to the (FR wheel). When the boost pressure output is performed (410: YE
S) is the total pressure increase output time counter CL at step 412.
If the pressure increase output has not been made after incrementing the value of "1" by one (410: NO), the process proceeds to step 41
Move to 4.

In the subsequent steps 414 to 424,
Left front wheel 2 (FL wheel), right rear wheel 3 (RR wheel), left rear wheel 4
(414, 418, 422), and if so, increments the value of the total pressure increase output time counter CL by one (416, 420). , 424), and terminates the process once. If CT = KT while repeating the processing of steps 404 to 424 (404: YES), step 42
Move to 6. In step 426, the counter memory C
The value of the total pressure increase output time counter CL is stored in M, and in subsequent steps 428 and 430, the total pressure increase output time counter C
L, the gate time counter CT is set to 0, and the process is once ended.

By the above processing, the execution cycle of the above processing ×
The value of the counter memory CM is set according to the frequency at which the pressure increase output is generated within the time KT. Therefore, the counter memory CM has a value corresponding to the entry speed of the brake pedal 27. Returning to FIG. 5, when CM <KM (340: YES), a B pattern for increasing the pressure relatively slowly is set (360), and when CM ≧ KM (34)
(0: NO) sets the C pattern for increasing the pressure relatively steeply (380).

As described above, in the present anti-skid control device, when the vehicle speed VB becomes equal to or lower than KVB1 due to braking, the pulse increasing mode is set according to the pressure increasing speed until VB becomes equal to or lower than KVB1. Therefore, the amount of brake fluid (pressure oil) flowing out of the master cylinder 16, that is,
The entry speed of the brake pedal 27 becomes a value corresponding to each other before and after the vehicle body speed VB becomes equal to or less than KVB1, and it is possible to suppress a temporal change thereof. Therefore, even in the low-speed traveling region, the brake pedal feeling does not deteriorate, and the driver does not feel uncomfortable.

Next, the effect of the above processing will be described with reference to the time chart of FIG. Here, as a comparative example, a conventional apparatus for forcibly setting the pressure increase mode when the vehicle body speed VB becomes equal to or lower than KVB1 will be described. FIG.
(A) illustrates changes in the wheel speed VW and the vehicle speed VB,
(B) illustrates the brake pressure and the pedal stroke (entrance amount of the brake pedal 27) in the comparative example corresponding to the change, and (C) illustrates the brake pressure and the pedal stroke in the present device.

Until the vehicle speed VB becomes equal to or lower than KVB1, both the comparative example and the present apparatus show the same brake pressure behavior and pedal stroke behavior. That is, the brake pressure is initially in the pressure increasing mode, becomes a pressure decreasing mode when a slip occurs, becomes a holding mode when the wheel speed VW starts increasing, and becomes a pulse increasing mode when the slip converges,
When the slip increases again, the behavior of switching to the decompression mode is repeated. During this time, the pedal stroke increases stepwise each time the pressure increase output is performed.

Assume that the vehicle speed VB becomes equal to or lower than KVB1 at time t1 (in the example of FIG. 8, the pulse increasing mode is being executed in the pattern A). In this case, in the comparative example of FIG. 8B, when the currently executing pulse increasing mode ends at time t2, the pressure increasing mode is set. For this reason, the brake pressure and the pedal stroke increase sharply at the time t2, giving the driver an uncomfortable feeling.

On the other hand, in the present apparatus shown in FIG.
At time t1 when VB≤KVB1, the pulse increase mode of the pattern B or pattern C is set (360, 3).
80). This pattern has enough time (at least 660m
s) Since the braking operation is continued, the brake pressure and the pedal stroke increase at a constant gradient until the braking operation is completed.
Moreover, since the pattern is selected according to the counter memory CM (340), the gradient of the pedal stroke is very similar to the gradient before time t1. Therefore, with this device, the vehicle can be safely stopped with almost no uncomfortable feeling for the driver.

The above-described embodiment is an embodiment corresponding to claims 2 and 3, and includes wheel speed sensors 5-8.
And steps 120 to 16 in the electronic control circuit 50
0 is the slip state detection means, the actuator 2
The processes of steps 1 to 24, 31 to 34, and steps 210 to 380 in the electronic control circuit 50 correspond to the brake pressure adjusting means, respectively.

Next, another embodiment of the pulse increase mode calculation processing will be described. In the present embodiment, the configuration of the anti-skid control device, the main routine, and the control mode calculation process are the same as those shown in FIGS. 1 to 4, and the pedal entry estimation routine in FIG. 6 is not executed.
In this embodiment, the pattern of the pulse increase mode is set as shown in Table 2.

[0046]

[Table 2]

That is, the A pattern and the B pattern are the same as in the above-described embodiment, and the C pattern is KU = 0 m
s, KH = 100 ms, N = 20p, that is, no boost output is generated and only the hold output is output for 2 seconds (100 ms × 2
0) It is a continuous pattern. When the vehicle speed VB becomes equal to or lower than KVB1 during the ABS control (222: NO), the slip ratio SW becomes equal to or lower than KS1 (224: NO), and the process proceeds to step 234, the pulse increase mode calculation process of FIG. 9 is executed. I do. If the vehicle speed VB is higher than KVB1 (500: YES), the pattern A in the pulse increasing mode is set and the process returns to the main routine, as in the above-described embodiment.

If the vehicle speed VB is equal to or less than KVB1 (500: NO), the process proceeds to step 540, and it is determined whether the current wheel to be controlled is one of the front wheels 1 and 2. In the case of one of the front wheels 1 and 2 (540: Y
ES), at step 560, the B pattern of the pulse increase mode is set, and the process returns to the main routine. If the wheel to be controlled is one of the rear wheels 3 and 4, (540:
NO), at step 580, set the C pattern of the pulse increase mode, and return to the main routine. By the above-described processing, the mode of increasing the brake pressure between the front wheels 1 and 2 and the rear wheels 3 and 4 can be made different.

The effect of this processing is illustrated in the time chart of FIG. Until the vehicle speed VB becomes equal to or less than KVB1 at time t1, the front wheel brake pressure, the rear wheel brake pressure, and the pedal stroke change in the same manner as in FIG. Time t
If VB ≦ KVB1 at 1 (500: YES), the front wheel brake pressure is gradually increased according to the pulse increase mode of the B pattern, and the rear wheel brake pressure is held for 2 seconds (C pattern). Then, usually, the brake operation ends during this time.

As described above, in this embodiment, when the vehicle speed VB becomes equal to or lower than KVB1 due to braking, only the brake pressure of the front wheels 1 and 2 is increased and the brake pressure of the rear wheels 3 and 4 is maintained. Therefore, the brake fluid flows out only from the master cylinder 16 toward the wheel cylinders 11 and 12. Therefore, even if the pulse increase mode is continued, the movement amount (pedal stroke) of the brake pedal 27 is halved,
Does not give the driver a sense of incompatibility.

The above-described embodiment is an embodiment corresponding to claims 1 and 3, and the wheel speed sensors 5 to 8
And steps 120 to 16 in the electronic control circuit 50
0 is the slip state detection means, the actuator 2
The processes of steps 1 to 24, 31 to 34, and steps 210 to 234 and 500 to 580 in the electronic control circuit 50 correspond to brake pressure adjusting means, respectively.

The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present invention. For example, in the processing of FIG. 9, the brake pressure of the rear wheels 3 and 4 is held,
The same effect can be expected simply by changing the timing of increasing the brake pressure between the front and rear wheels. Further, even if the pressure increase timing is made different between the four wheels, the pressure increase is made between the right hydraulic system (front left wheel 2, right rear wheel 3) and the left hydraulic system (front right wheel 1, left rear wheel 4) in FIG. The timing may be different. Further, after increasing the pressure increasing timing, the pressure increasing speed may be set according to the value of the counter memory CM (FIG. 6). In this case, the vehicle can be stopped safely without further discomfort.

Further, the above-described anti-skid control device does not have a pressure source other than the master cylinder 16, but the present invention can be applied to an anti-skid control device further provided with a hydraulic source such as a pump. it can. However, in an anti-skid control device including a hydraulic source such as a pump in addition to the master cylinder 16, a phenomenon (so-called kickback) in which a brake pedal is pushed back during a braking operation occurs,
I don't feel much discomfort even if the brake pedal feel changes. On the other hand, in the anti-skid control device having no pressure source other than the master cylinder 16, kickback does not occur, and a sense of discomfort due to a change in brake pedal feeling is particularly strongly felt. Therefore, there is a strong demand for prevention of deterioration of the brake pedal feeling.

In each of the above embodiments, the master cylinder 1
Since the brake pedal feeling can be prevented from deteriorating with respect to the anti-skid control device having no pressure source other than 6, the effect of the present invention becomes more remarkable. Also,
In each of the above embodiments, since there is no pressure source such as a pump, further cost reduction and noise reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an anti-skid control device to which the present invention has been applied.

FIG. 2 is a flowchart showing a main routine by the control device.

FIG. 3 is a flowchart showing a control mode calculation process of the routine.

FIG. 4 is a flowchart showing a continuation of the control mode calculation process.

FIG. 5 is a flowchart illustrating a pulse increase mode calculation process of the process.

FIG. 6 is a flowchart illustrating a pedal entry estimation routine.

FIG. 7 is a time chart illustrating an output mode in a pulse increasing mode;

FIG. 8 is a time chart showing the effect of the above processing.

FIG. 9 is a flowchart illustrating another mode of the pulse increase mode calculation process.

FIG. 10 is a time chart showing the effect of the processing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Right front wheel 2 ... Left front wheel 3 ... Right rear wheel 4 ... Left rear wheel 5, 6, 7, 8 ... Wheel speed sensor 11, 12, 13, 14 ... Wheel cylinder 1
6 Master cylinder 21, 22, 23, 24, 31, 32, 33, 34 Actuator 27 Brake pedal 29 Stop switch 37, 39 Reservoir 50 Electronic control circuit

Claims (3)

[Claims] 1. A slip state detecting means for detecting a slip state of a wheel during braking of a vehicle, a master cylinder for generating a fluid pressure in response to an operation of a brake pedal, and a slip state detected by the slip state detecting means is appropriate. And a brake pressure adjusting means for increasing and decreasing the brake pressure of the wheels so that the brake pressure of the wheels is increased. The brake pressure adjusting means increases the brake pressure using the fluid pressure generated by the master cylinder. In the anti-skid control device, the brake pressure adjusting means increases the brake pressures of a plurality of wheels at different timings when the vehicle speed becomes equal to or lower than a predetermined speed due to the braking, so that the fluid flows out of the master cylinder. An anti-skid control device characterized in that the amount of change over time is suppressed. 2. A slip state detecting means for detecting a slip state of a wheel during braking of a vehicle, a master cylinder for generating a fluid pressure in response to an operation of a brake pedal, and a slip state detected by the slip state detecting means is appropriate. And a brake pressure adjusting means for increasing and decreasing the brake pressure of the wheels so that the brake pressure of the wheels is increased. The brake pressure adjusting means increases the brake pressure using the fluid pressure generated by the master cylinder. In the anti-skid control device, when the vehicle speed becomes equal to or lower than a predetermined speed due to the braking, the brake pressure adjusting means may adjust the outflow amount of the fluid from the master cylinder until the vehicle speed becomes equal to or lower than the predetermined speed. An anti-skid control device, wherein the brake pressure is increased or decreased so as to have a corresponding value. 3. The brake pressure adjusting means increases the brake pressure by supplying the fluid flowing out of the master cylinder as it is without having a pressure source of the brake pressure other than the master cylinder. 3. The anti-skid control device according to claim 1, wherein the brake pressure is reduced or maintained by inhibiting the outflow of the fluid from the master cylinder.