JP3653101B2 - Anti-skid device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an anti-skid device, and more particularly to avoiding a shortage of braking force based on excessive pressure reduction during low-speed traveling.
[0002]
[Prior art]
An anti-skid device is generally configured as follows. (A) a hydraulic pressure source, (b) a reservoir, (c) a hydraulic pressure source, a reservoir, and a brake cylinder of a brake device that suppresses rotation of a vehicle wheel. A hydraulic control valve device that switches between a pressure-increasing state in which the hydraulic pressure of the brake cylinder is increased by communicating with the source and a pressure-reducing state in which the hydraulic pressure of the brake cylinder is decreased by communicating with the reservoir; Wheel speed acquisition means for acquiring wheel speed; (e) travel speed acquisition means for acquiring vehicle travel speed; and (f) wheel speeds acquired by the wheel speed acquisition means and travel speed acquisition means, respectively. The hydraulic pressure control valve device is switched based on the traveling speed, and is configured to include control means for controlling the wheel slip to an appropriate range.
[0003]
In such an anti-skid device, the pressure is excessively reduced during low-speed traveling, and the braking force tends to be insufficient. For example, in the anti-skid device described in Japanese Patent Laid-Open No. 3-292247, the fact that the traveling speed is acquired from the wheel speed is a cause of excessive decompression. When the traveling speed is acquired from the wheel speed, it is acquired based on the fastest wheel speed of the four wheels and the deceleration detected by the longitudinal acceleration sensor. The wheel speed fluctuates due to pressure fluctuations, and the traveling speed fluctuates accordingly. If the traveling speed and the wheel speed are reduced, the influence of these fluctuations appears to be large and the slip ratio greatly fluctuates. In actuality, it is judged that the slip ratio does not exceed the appropriate range, but is reduced. Tends to be over-depressurized. Therefore, in the anti-skid device described in the above publication, when the traveling speed becomes a set value or less, based on the deceleration detected by the longitudinal acceleration sensor when the traveling speed becomes the set value or less, The traveling speed is acquired regardless of the wheel speed, so that the decompression is not excessively performed.
[0004]
[Problems to be solved by the invention]
However, there are various causes other than the cause described in the above publication as the cause of excessive decompression during low-speed traveling. For example, one of the causes is that the wheel speed is acquired based on the detection result of the pulse type rotation sensor. The pulse-type rotation sensor rotates with a wheel and has a rotor having a large number of teeth on the periphery, a coil and a permanent magnet attached to the vehicle body, and converts an alternating voltage generated in the coil as the rotor rotates into a pulse signal. It has a waveform shaper and can calculate the wheel speed from the period of the pulse signal. However, as will be described in detail later in the section of the embodiment, if the traveling speed becomes low, the pulse period becomes long and the delay in detecting the wheel speed becomes large, which contributes to excessive decompression.
[0005]
Excessive decompression due to the use of this pulse type rotation sensor cannot be prevented by the means described in the publication. Even if the acquisition of the traveling speed based on the wheel speed is stopped, if the wheel speed is acquired based on the detection result of the pulse type rotation sensor, excessive decompression due to the delay in the detection of the wheel speed cannot be avoided.
An object of the present invention is to provide an anti-skid device that can avoid a shortage of braking force as much as possible regardless of the cause of excessive decompression during low-speed traveling.
[0006]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the invention of claim 1 is configured such that (a) the hydraulic pressure source 1, (b) the reservoir 2, (c) the hydraulic pressure of the brake cylinder of the brake device, as shown in FIG. The control means 6 of the anti-skid device including the hydraulic pressure control valve device 3 to be controlled, (d) wheel speed acquisition means 4, (e) travel speed acquisition means 5 and (f) control means 6 is (1) predetermined. End means for ending the control of the hydraulic control valve device when the end condition is satisfied, and (2) the end condition is not satisfied and the traveling speed isWhen the speed is lower than this, the brake cylinder hydraulic pressure is likely to be excessively reduced due to a delay in detection of the wheel speed by the pulse type rotation sensor.In the case of a set value or less, while controlling the slip of the wheel to an appropriate range, the hydraulic pressure increase gradient of the brake cylinder is set to be steeper than when the drive speed exceeds the set value. It is a summary to include the means.The wheel speed acquisition means 4 is a pulse type rotation sensor that outputs a pulse type signal as the wheel rotates.
  Furthermore, the invention of claim 2 is a vehicle that travels at a low speed.Pressure increaseThe control means is designed to make the pressure increase gradient of the brake cylinder pressure steep when the traveling speed is below the set value and the previous pressure reducing time of the brake cylinder pressure is longer than the set time. And the invention of claim 3 is for low speed running.Pressure increaseThe gist of the present invention is that the control means includes means for making the pressure increase gradient of the hydraulic pressure of the brake cylinder steeper as the pressure reduction time becomes longer.
  The invention of claim 4 includes (a) a hydraulic pressure source, (b) a reservoir, (c) a hydraulic pressure control valve device, (d) a wheel speed acquisition means, (e) a traveling speed acquisition means, and (f) a control means. Including means for controlling the anti-skid device, (1) Starting means for starting control of the hydraulic control valve device when a predetermined start condition is satisfied; (2) Ending means for ending the control of the hydraulic control valve device when a predetermined ending condition is satisfied; (3) Even if the traveling speed at the start of control of the hydraulic control valve device is larger than a set value, the slip of the wheel is within an appropriate range when the end condition is not satisfied and the traveling speed is less than the set value. And a pressure increase control means for low-speed traveling that makes the pressure increase gradient of the hydraulic pressure of the brake cylinder steeper than when the traveling speed exceeds the set value.
[0007]
Brake cylinder hydraulic pressureFor example, when the pressure increase is performed by switching between the pressure-increasing state and the pressure-reducing state of the hydraulic pressure control valve device 3, the pressure-increasing gradient is set to be longer or the pressure-reducing time is shortened. It can be made abrupt by setting or switching only to the pressure increasing state. Further, the pressure increase gradient may be continuously increased while the brake cylinder pressure is increased, or may be increased only when the pressure increase is started.
The same applies to the case where the hydraulic pressure control valve device 3 is switchable between the pressure-increasing state, the holding state, and the pressure-reducing state, and the pressure increase is performed by switching between the pressure-increasing state and the holding state.
Furthermore, when the pressure increase is performed by sudden pressure increase and slow pressure increase, it can be made substantially steep by lengthening the rapid pressure increase time and shortening the slow pressure increase time. In this way, the overall gradient of the pressure increase consisting of sudden pressure increase and slow pressure increase substantially increases.
[0008]
[Action]
When the running speed is below the set value in this wayBrake cylinder hydraulic pressureIf the pressure increase gradient is made steep, an excessive decrease in the brake cylinder pressure can be quickly recovered even if the pressure is reduced excessively.
[0010]
【The invention's effect】
As described above, according to the present invention, even if the pressure is excessively reduced during low-speed traveling, the excessive decrease in the brake cylinder pressure is rapidly recovered by abruptly increasing the pressure increasing gradient, so that the braking force is insufficient. It can be small, the extension of the braking distance can be suppressed, and the vehicle can be stopped satisfactorily.
Further, since the present invention compensates for the shortage of the brake cylinder pressure by making the pressure increase gradient steep, the cause of the excessive pressure reduction of the brake cylinder pressure is described in the above publication. Insufficient braking force can be avoided even if the speed varies or the wheel speed is delayed due to the use of a pulse rotation sensor.
[0011]
【Example】
Hereinafter, an embodiment when the present invention is applied to an anti-skid device of a hydraulic brake device for a four-wheel vehicle will be described in detail with reference to the drawings.
In FIG. 2, 10 is a tandem master cylinder as a hydraulic pressure source. A brake pedal 14 is connected to the master cylinder 10 via a booster 12, and hydraulic pressures of the same height are generated in two independent pressurizing chambers of the master cylinder 10 in response to the depression operation of the brake pedal 14. To do. A reservoir 16 is attached to the master cylinder 10 and replenishes brake fluid thereto.
[0012]
The hydraulic pressure generated in each pressurizing chamber of the master cylinder 10 is applied to the front brake cylinders 30 and 32 and the rear brake cylinders 34 and 36 of the brake devices provided on the left and right front wheels 20 and 22 and the left and right rear wheels 24 and 26, respectively. Supplied. The hydraulic brake device of the present embodiment is a two-line front and rear system. Since the basic structure of the front and rear brake systems is substantially the same, the same reference numerals will be given to the front and rear systems for the same operation, and the front wheel brake system will be mainly described. The system will be supplemented as necessary.
[0013]
In the middle of the main fluid passage connecting the master cylinder 10 and the front brake cylinders 30 and 32, there are two electromagnetic control valves 40 as hydraulic pressure control valve devices corresponding to the front brake cylinders 30 and 32, respectively. Thus, the main liquid passage is divided into a master cylinder side passage 42 and a brake cylinder side passage 44. In the brake system of the rear wheels 24 and 26, as is apparent from the figure, the electromagnetic control valve 40 is common to the rear brake cylinders 34 and 36.
[0014]
Each electromagnetic control valve 40 is a switching valve that can be switched to three states of a pressure increasing state, a holding state, and a pressure reducing state. As shown in FIG. 2, the pressure increasing state is such that the master cylinder side passages 42 are communicated with the corresponding brake cylinder side passages 44, and the corresponding front brake cylinders are supplied by the brake fluid supplied to the master cylinder side passages 42. In this state, the hydraulic pressures 30 and 32 are increased. The holding state is a state in which all of the master cylinder side passage 42, the brake cylinder side passage 44, and the reservoir passage 48 are blocked and the hydraulic pressures of the corresponding front brake cylinders 30 and 32 are kept constant. Further, in the reduced pressure state, the corresponding brake cylinder side passages 44 are communicated with the common reservoir 50 via the reservoir passages 48, and the front brake cylinders 30, In this state, the hydraulic pressure of 32 is reduced.
[0015]
The brake fluid stored in the reservoir 50 is pumped up by the pump 52. The pump 52 is driven by a motor 54, and the brake fluid in the reservoir 50 is supplied to the master cylinder side passage 42 through a pump passage 60 having a check valve 58 while pulsation is eased by an accumulator 56. A pair of check valves 64 having a forward direction from the reservoir 50 to the accumulator 56 are provided before and after the pump 52 so that the brake fluid does not flow back to the reservoir 50.
[0016]
A bypass passage 70 that bypasses each electromagnetic control valve 40 is connected between the master cylinder-side passage 42 and the brake cylinder-side passage 44, and each front brake cylinder 30, 32 side is in the middle of the bypass passage 70. Check valves 72 each having a forward direction from the first side toward the master cylinder 10 are provided. Therefore, when the depression of the brake pedal 14 is released and the master cylinder hydraulic pressure is lowered, the brake fluid is quickly returned to the master cylinder 10 by bypassing the electromagnetic control valves 40 from the front brake cylinders 30 and 32. It is.
[0017]
Switching of the electromagnetic control valve 40 is performed by the control device 80. The control device 80 is mainly composed of a microcomputer, and the wheels from the output signals of the rotation sensor 82 for detecting the rotational speeds of the left front wheel 20 and the right front wheel 22 and the average rotational speeds of the left and right rear wheels 24 and 26, respectively. The slip state of 20, 22, 24, 26 is estimated, and the amount of current supplied to the solenoid 84 of each electromagnetic control valve 40 is controlled, so that the electromagnetic control valve 40 is switched to the three states, and the left front wheel 20 and Control is performed so that the slip ratio of the right front wheel 22 and the average slip ratio of the left and right rear wheels 24 and 26 become appropriate values. The rotation sensor 82 is a pulse type rotation sensor, and the number of pulses corresponding to the wheel speed is supplied to the control device 80. The control device 80 is connected to a brake switch 86 that detects depression of the brake pedal 14.
[0018]
As shown in FIG. 3, a flag F and a counter 92 are provided together with a working memory in the RAM of the microcomputer constituting the main body of the control device 80. Further, a control mode selection map for anti-skid control shown in FIG. 4 is stored in the ROM of the microcomputer. This control mode selection map shows the wheel speed V_WIs the reference speed V_SN, V_SHWheel acceleration V_W'Is the reference acceleration G₁ , G₂ It is a map which selects whether it is pressure reduction, pressure increase, or holding depending on whether it is larger. Control reference speed V_SHAnd control reference speed V_SNIs calculated by multiplying the running speed of the car by a certain ratio, and the control reference speed V_SHIs V_SNSet to a lower value. Reference acceleration G₂ Is a positive value and the reference acceleration G₁ Are negative values, and these are set in advance to a constant value.
[0019]
In the control mode selection map, the depressurization mode is a mode in which the brake cylinder pressure is rapidly decreased while the electromagnetic control valve 40 is switched to the depressurized state, and the holding mode is the brake in which the electromagnetic control valve 40 is held. This is a state in which the cylinder pressure is maintained at a certain level. The pulse increasing mode is a mode in which the brake cylinder pressure is gradually increased by alternately switching the electromagnetic control valve 40 between the pressure increasing state and the holding state, and the time between the pressure increasing state and the holding state is set in advance. Has been.
[0020]
Further, the ROM stores an anti-skid control routine shown in the flowchart of FIG. The anti-skid control will be described below based on this flowchart.
[0021]
First, in step 1 (hereinafter abbreviated as S1. The same applies to other steps), the detection value of the rotation sensor 82 is read and the wheel speed (wheel peripheral speed) V is read._W, Wheel acceleration V_W', Traveling speed Vs, vehicle deceleration and control reference speed V_SN, V_SHIs calculated. The traveling speed Vs is always estimated to be the fastest speed among the four wheel speeds, and after the deceleration of the fastest wheel exceeds a preset upper limit, the deceleration is set to the upper limit. The traveling speed Vs is calculated with a fixed value. Next, S2 is executed and it is determined whether or not the flag F is set. The determination result is NO, and it is determined whether or not the anti-skid control start condition is satisfied in S3.
[0022]
In this embodiment, the anti-skid control start condition is that the brake pedal 14 is depressed, the wheel speed V_WIs the reference speed V_SNAnd wheel acceleration V_W'Is the reference acceleration G₁ It is the following. If these anti-skid control start conditions are not satisfied, the determination result in S3 is NO, the flag is reset in S6, the counter 92 is cleared, the electromagnetic control valve 40 is switched to the pressure-increasing state, and the routine is executed. Ends.
[0023]
If the anti-skid control start condition is satisfied, the determination result in S3 is YES, and after the flag F is set in S4, S5 is executed to determine whether or not the anti-skid control end condition is satisfied. The anti-skid control end condition is that the depression of the brake pedal 14 is released. If the end condition is satisfied, the determination result in S5 is YES, and the execution of the routine is ended after the execution of S6.
[0024]
If the anti-skid control start condition is satisfied and the anti-skid control end condition is not satisfied, S7 is executed, and the control mode is selected. Wheel speed V calculated in S1_WAnd wheel acceleration V_WThe control mode is selected according to the control mode selection map shown in FIG.
[0025]
After the selection, S8 is executed, and it is determined whether or not the selected control mode is the decompression mode. If the depressurization mode, the determination result in S8 is YES, and after the count value C of the counter 92 is incremented by 1 in S9, a depressurization command signal is output in S10, thereby switching the electromagnetic control valve 40 to the depressurization state. As a result, the brake cylinder pressure is reduced, and the wheel slip is reduced. While the decompression mode is selected, S1, S2, S5, S7 to S10 are repeatedly executed, and the decompression time is measured by the counter 92.
[0026]
If the rotation of the wheel recovers and the pulse increase mode or the hold mode is selected, the determination result in S8 is NO and S11 is executed to determine whether or not the pulse increase mode is selected. If it is not the pulse increase mode, it is the holding mode, the determination result in S11 is NO, a holding command signal is output in S12, and the electromagnetic control valve 40 is switched to the holding state.
[0027]
On the other hand, if the selected control mode is the pulse increase mode, the determination result in S11 is YES, S13 is executed, and the rapid pressure increase time at the start of pressure increase is calculated. As described above, the pressure increase is performed gently by repeatedly switching the electromagnetic control valve 40 between the pressure increase state and the hold state, but at the start of pressure increase, the hold time is made shorter than the preset value, As shown by the solid line in FIG. 8C, the pressure increase gradient is made steep so that the rise of pressure increase is improved. Although the increase in the brake cylinder pressure is shown by a single straight line in the figure, the switching between the pressure increasing state and the holding state is repeated, and the brake cylinder pressure is actually increased stepwise. It is done. The calculation of the pressure increase time in S13 is a calculation of the sudden pressure increase time by shortening the holding time at the start of the pressure increase, and the rapid pressure increase time is the pressure reduction time (hereinafter referred to as C) expressed by the count value C of the counter 92. (Represented by The rapid pressure increase time becomes longer as the pressure reduction time C is longer.
[0028]
After calculation of the sudden pressure increase time, S14 is executed, and the pressure reduction time C is set to the set time C._AIt is determined whether or not this is the case. Depressurization is set time C_AWhen the above is performed, the determination result in S14 is YES, and in S15, it is determined whether or not the traveling speed of the automobile is equal to or less than a set value (15 km / h in this embodiment). If it is equal to or less than the set value, the determination result in S15 is YES, and in S16, the constant pressure α is added to the rapid pressure increase time calculated in S13 to obtain the rapid pressure increase time during low-speed traveling, and the counter 92 is cleared in S17. .
[0029]
Depressurization is set time C_AIf it is performed for a shorter time, the determination result in S14 is NO, and the pressure reduction is performed for the set time C._AEven if the above is performed, if the traveling speed is larger than the set value, the determination result in S15 is NO, and S16 and S17 are not executed. Therefore, when either S14 or S15 is NO, the pressure increase command signal and the sudden pressure increase time obtained in S13 are output in S18, whereby the electromagnetic control valve 40 is switched to the pressure increase state and increased. At the start of pressure, the brake cylinder pressure is increased as shown by the solid line in FIG. Further, when both the determination results of S14 and S15 are YES and the sudden pressure increase time during low-speed traveling is obtained in S16, the pressure increase command signal obtained in S18 and the sudden pressure increase time during low-speed traveling obtained in S16 are output. As a result, the electromagnetic control valve 40 is switched to the pressure-increasing state, and at the start of pressure-increasing, the brake cylinder has a steeper slope than when the traveling speed exceeds the set value as shown by a two-dot chain line in FIG. The pressure is increased.
[0030]
As described above, when the travel speed of the automobile is equal to or lower than the set value, the rapid pressure increase time at the start of the pressure increase is increased by the constant value α when the travel speed is low. This is because there is a case where the brake cylinder pressure is excessively decreased due to a delay in detection of the wheel speed. The average delay T of the detection time can be obtained by the following equation.
T = ΔT / 2 + wheel speed calculation cycle / 2
However,
ΔT: Time interval when the pulse of the rotation sensor 82 falls at a speed of Akm / h
[0031]
The calculation of the wheel speed is performed based on the falling edge of the pulse signal, and the wheel speed is calculated at the timings a, c, and f during the calculation timings a to f shown in FIG. While the wheel speed changes every moment, the wheel speed obtained by the calculation is the average value of the wheel speed between successive falling edges, and half the falling time interval of the successive pulse signals. Considering that the wheel speed at the time is an average speed, a delay of ΔT / 2 occurs with respect to the latest falling time. In addition, there is a difference between the minimum 0 and the maximum calculation cycle between the fall of the pulse signal and the calculation timing, and it can be considered that the delay based on the calculation cycle is equal to half of the calculation cycle on average. The calculation delay can be caused by the combined time. For example, if the rotor has 48 teeth, the pulse generation interval is 13 ms at a speed of 10 km / h. If the calculation period of the wheel speed is 5 ms, the average is 9 ms (minimum 6.5 ms, maximum 11.5 ms). ) Delay occurs.
[0032]
During the calculation timing shown in FIG. 6, at the timings b, d, and e, there is no falling of the pulse signal with the previous calculation timing, and in this case, the wheel speed is the previously calculated wheel speed and the wheel. It is estimated based on the vehicle body acceleration when the speed is obtained.
[0033]
If there is a delay in the detection of the wheel speed in this way, the pressure is reduced excessively. When a delay occurs in the detection of the wheel speed and a delay of Δt time occurs at the end of the pressure increase as shown in FIG. 7A, the brake cylinder pressure increases by the delay. In addition, as shown in FIG. 7B, when a delay of Δt time occurs at the end of the decompression, the decompression is excessively performed by the delay. These pressure increase end delays and pressure reduction end delays occur with the same probability, but since the pressure reduction is performed by rapid pressure reduction and the pressure increase is performed by slow pressure increase, the pressure reduction is larger and the brake cylinder pressure is excessively reduced. .
[0034]
In addition, when there is a delay in the end of pressure increase, the slip proceeds even if the brake cylinder pressure is not so high, so as shown in FIG. 7C, the pressure is greatly reduced to reduce the large slip. This also results in excessive vacuum. Even if there is a delay in the end of the pressure increase, the increase in the brake cylinder pressure due to the slow pressure increase is slight, but the pressure is excessively reduced due to the large pressure reduction. The phenomena shown in FIGS. 7A, 7B, and 7C are caused by overlapping all or part of the phenomenon, and the brake cylinder pressure is excessively reduced.
[0035]
Thus, when the running speed is low, the brake cylinder pressure may be excessively decreased due to the detection delay of the wheel speed. Even if the detection delay occurs in the wheel speed, the wheel speed may increase due to an increase in the friction coefficient of the road surface. There is a case where the pressure is not excessively reduced because the speed is recovered quickly and the pressure reduction is completed quickly or the wheel speed detection delay is relatively small. In such a case, if the brake cylinder pressure sudden increase time is lengthened, the wheel speed and the wheel acceleration rapidly decrease and the slip increases as shown by a two-dot chain line in FIG. In the example, the decompression time is measured, and it is determined whether the decompression time has actually exceeded the set value. Since the determination result in S14 is NO and the rapid pressure increase time is not lengthened, it is possible to prevent the brake cylinder pressure from being excessively increased and the slip from proceeding.
[0036]
As described above, in this embodiment, the wheel speed is detected by the pulse-type rotation sensor 82, and there is a tendency that the detection of the wheel speed is delayed at the time of low speed traveling, and the pressure is reduced excessively. By increasing the brake cylinder pressure with a steep slope when the pressure is increased, the braking force is not insufficient, and the automobile can be stopped without extending the braking distance.
[0037]
As is clear from the above description, in this embodiment, the rotation sensor 82, the area for storing S1 of the ROM, and the portion for executing S1 of the CPU constitute the wheel speed acquisition means 4, and the traveling speed acquisition means 5 is constituted. Further, the area for storing S2 to S8, S10 to S12, and S18 of the ROM and the part for executing these steps of the CPU constitute the control means 6, the area for storing S9 and S13 to S17 of the ROM, and the CPU and RAM. The part that executes these steps constitutes the pressure increase control means 7 during low-speed running.
[0038]
In the above embodiment, α added to the sudden pressure increase time at the start of pressure increase in order to calculate the sudden pressure increase time during low-speed driving was set to a constant value, but when the pressure reduction time is long, α is increased. Α can be changed accordingly.
[0039]
In the above embodiment, the traveling speed of the automobile is calculated based on the wheel speed. However, the traveling speed may be acquired regardless of the wheel speed by a Doppler ground vehicle speed sensor.
[0040]
Furthermore, the traveling speed is estimated by the wheel speed and the wheel acceleration, and there is an advantage that the longitudinal acceleration sensor is unnecessary and the cost and weight are low. However, the longitudinal acceleration sensor is provided and the anti-skid control is provided. After is started, the traveling speed may be estimated from the traveling speed and the longitudinal acceleration at the start.
[0041]
Further, in the above embodiment, when the decompression time is shorter than the set time, the rapid pressure increase time is not lengthened, and the area for storing S9, S14 and S17 of the computer ROM and the CPU and RAM are excessive. Although the pressure increase preventing means is configured, it is not essential to provide such means.
[0042]
Furthermore, in the above embodiment, the hydraulic control valve device is switched to the pressure-increasing state, the holding state, and the pressure-reducing state.
[0043]
In addition, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a block diagram conceptually showing the structure of the present invention.
FIG. 2 is a system diagram showing a hydraulic brake device for a four-wheel vehicle equipped with an anti-skid device according to an embodiment of the present invention.
FIG. 3 is a diagram showing a configuration of a RAM of a computer constituting the main body of the control device of the anti-skid device.
FIG. 4 is a diagram showing a control mode selection map stored in the ROM of the computer.
FIG. 5 is a flowchart showing an anti-skid control routine stored in the ROM.
FIG. 6 is a diagram for explaining generation of a wheel speed detection delay.
FIG. 7 is a diagram for explaining excessive reduction of brake cylinder pressure that occurs when a detection delay of wheel speed occurs.
FIG. 8 is a graph showing the relationship between time, wheel speed, wheel acceleration, and brake cylinder pressure when the brake cylinder pressure is controlled by the anti-skid device.
FIG. 9 is a diagram for explaining a problem when the pressure increasing gradient is made steep when the pressure reduction is not excessively performed in the anti-skid device.
[Explanation of symbols]
10 Master cylinder
16 Reservoir
20 Front left wheel
22 Front right wheel
24 Left rear wheel
26 Right rear wheel
30, 32 Front brake cylinder
34, 36 Rear brake cylinder
40 Electromagnetic control valve
50 reservoir
80 controller
82 Rotation sensor

Claims (4)

A hydraulic source;
A reservoir,
The hydraulic pressure source is provided between the hydraulic pressure source, the reservoir, and a brake cylinder of a brake device that suppresses rotation of a vehicle wheel, and at least the brake cylinder communicates with the hydraulic pressure source to increase the hydraulic pressure of the brake cylinder. A hydraulic control valve device that switches between an increased pressure state and a reduced pressure state that reduces the hydraulic pressure of the brake cylinder by communicating the brake cylinder with the reservoir;
A wheel speed acquisition means for acquiring a rotation speed of the wheel , and a pulse type rotation sensor that outputs a pulse signal along with the rotation of the wheel;
Traveling speed acquisition means for acquiring the traveling speed of the vehicle;
An anti-static control device that switches the hydraulic pressure control valve device based on the wheel speed and the traveling speed acquired by the pulse-type rotation sensor and the traveling speed acquisition means, respectively, and controls the slip of the wheel to an appropriate range. In skid equipment,
The control means, (1) an end means for ending the control of the hydraulic control valve device when a predetermined end condition is satisfied; and (2) the end condition is not satisfied and the traveling speed However, when the speed is lower than this, the brake cylinder hydraulic pressure is likely to be excessively reduced due to a delay in detection of the wheel speed by the pulse-type rotation sensor. And a low-pressure running pressure increase control means for making the pressure increase gradient of the hydraulic pressure of the brake cylinder steeper than when the running speed exceeds the set value while controlling the slip of the wheel to an appropriate range. Anti-skid device featuring. The low-speed traveling when the pressure increase control means, the pressure increase gradient of the hydraulic pressure in the brake cylinder, and a traveling speed below the set value, and, when the hydraulic pressure in the last decompression time of the brake cylinder is longer than the set time 2. The anti-skid device according to claim 1, wherein the anti-skid device is sudden. The low-speed running when the pressure increasing control means, antiskid device according to pressure increase gradient of the hydraulic pressure in the brake cylinder, to claim 1 or 2 last decompression time includes means for longer steep.   A hydraulic source;
  A reservoir,
  Provided between the hydraulic pressure source, the reservoir, and a brake cylinder of a brake device that suppresses rotation of a vehicle wheel, and at least the brake cylinder communicates with the hydraulic pressure source to increase the hydraulic pressure of the brake cylinder. A hydraulic control valve device that switches between an increased pressure state and a reduced pressure state that reduces the hydraulic pressure of the brake cylinder by communicating the brake cylinder with the reservoir;
  Wheel speed acquisition means for acquiring the speed of the wheel;
  Travel speed acquisition means for acquiring the travel speed of the vehicle;
  Control means for switching the hydraulic control valve device based on the wheel speed and the traveling speed acquired by the wheel speed acquisition means and the traveling speed acquisition means, respectively, and controlling the slip of the wheel to an appropriate range;
In anti-skid equipment including:
  The control means is (1) Start means for starting control of the hydraulic control valve device when a predetermined start condition is satisfied; (2) Ending means for ending the control of the hydraulic control valve device when a predetermined ending condition is satisfied; (3) Even if the traveling speed at the start of the control of the hydraulic control valve device is larger than a set value, the slip of the wheel is within an appropriate range when the end condition is not satisfied and the traveling speed becomes a set value or less. And a low pressure traveling pressure increase control means for making the pressure increasing gradient of the hydraulic pressure of the brake cylinder steeper than when the traveling speed exceeds the set value.
An anti-skid device comprising:

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