JPH06183321A - Brake control device - Google Patents

Abstract

PURPOSE:To shorten the braking distance by making adjustment so that the braking force for the wheels judged to be in the rear by means of a judgment means may be less powerful than the braking force for the wheels judged to be in the front by means of a judgment means while driving at a low speed by applying the brake. CONSTITUTION:Assuming that shafts 1, 2 are front shafts and shafts 3, 4 are rear shafts, an emergency brake changeover valve 7 is changed and air is flowed in an emergency brake device 8 when an emergency brake command signal is turned on. Air passing through a relay valve 6 is flowed in control valves 1e, 2e, 3e, 4e and brake cylinder pressure (BC pressure) starts a sudden increase. Arrival BC pressure of the front shaft indicated on a front shaft BC pressure variation line S21 is maintained at BC pressure higher than the arrival BC pressure indicated on a conventional BC pressure variation line S20 by DELTABC pressure. Arrival BC pressure of a rear shaft indicated on a rear shaft BC pressure variation line S22 is maintained conversely at BC pressure lower than the arrival BC pressure indicated on the conventional BC pressure variation line S20 by DELTABCb.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for controlling a brake in a vehicle, and more particularly to a brake control system suitable for use in a railway vehicle.

[0002]

2. Description of the Related Art Improving the traveling speed of a railway vehicle is one of the most important issues. Currently, the limited travel distance when the emergency brake is activated is about 600 meters,
The current maximum speed of conventional lines within this regulation is approximately 130k.
m / h.

By the way, when the maximum speed is increased from 120 km / h to 130 km / h, a larger emergency braking force is required to maintain the above-mentioned limited travel distance, which causes a phenomenon that the wheels slide on the rail. It was feared to occur. This occurs when a braking force exceeding the adhesive force (friction force) between the wheel and the rail is applied.

Therefore, the load applied to the truck is measured, the braking force commensurate with the load is calculated to give an appropriate brake cylinder pressure (BC pressure), and a valve for adjusting the BC pressure is provided to occasionally brake. A method has been proposed in which the brakes are kept applied while loosening the force and re-adhering the wheels and rails.

[0005]

However, if an attempt is made to further increase the maximum traveling speed in the above system, the frequency of gliding during emergency braking will increase, and another brake will be used in order to adhere to the above-mentioned limited traveling distance. It is necessary to use it together with a mechanism (eg rail brake). In other words, not only is it necessary to make a major system change, but also a considerable cost increase is inevitable.

In this system, the same BC pressure is set on all axles. However, when decelerating due to sudden braking, the weight of the axles moves between the axles, and the front axle is heavier than the rear axle, causing sliding mainly in the rear axle. ing. Therefore, in this method, the BC pressure of the adhesive force is not applied to each axis to the utmost, the brake stop distance cannot be shortened sufficiently, and it is difficult to further increase the maximum traveling speed.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a brake control system capable of shortening the braking distance while using the existing braking mechanism.

[0008]

In order to solve the above problems, the present invention provides a brake control system used in a vehicle having a plurality of wheels and a brake for braking the wheels. At the time of traveling, determination means for determining the front-rear relationship of the wheels with respect to the traveling direction, and during deceleration traveling by the braking operation of the vehicle, than the braking force for the wheels determined to be the front side by the determination means
It is characterized by further comprising: an adjusting unit that adjusts the braking force with respect to the wheel determined to be the rear side by the determining unit to be smaller.

[0009]

In the braking operation, the wheel determined to be the rear side of the traveling vehicle receives a smaller braking force than the wheel determined to be the front side. Therefore, the front wheels are braked with a larger force, and the rear wheels are braked with a smaller force.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a vehicle according to the present invention. In the figure, 1, 2, 3, and 4 are the first to fourth axes of the wheels of the railway vehicle, respectively. These four axes have
There are similar related parts, which are shown below with the attached symbols a to e. First, 1a, 2a, 3a and 4a are wheels fitted to respective shafts, and 1b, 2b, 3b and 4b.
Is a brake shoe that is pressed against each wheel during brake operation. Further, 1c, 2c, 3c and 4c are cylinders for operating the brake shoe, 1d, 2d, 3d and 4d are preliminary brake switching valves, and finally 1e, 2e, 3e and 4e are control valves for cylinder pressure. is there.

Next, 9 is a proportional valve into which high-pressure air sent from the compressor is sent. The proportional valve 9 outputs air by an air pressure proportional to the current instruction value of the control device 10. Further, 7 is an emergency brake switching valve, which operates so that air is introduced from the proportional valve 9 into the relay valve 6 when the vehicle is normally stopped. Then, when the emergency brake is applied by the driver of the vehicle and the emergency brake signal is output from the control device 10, the air inflow / outflow system is switched. That is, during emergency braking, high-pressure air is sent into the emergency braking device 8, flows out at a predetermined air pressure set in the emergency braking device 8, and flows into the relay valve 6. Then, the air that has passed through the relay valve 6 flows into the control valves 1e, 2e, 3e, 4e, and the cylinders 1c,
Activate 2c, 3c, 4c.

Reference numeral 5 is a direct-through spare brake, which is a spare brake used by the spare brake switching valves 1d, 2d, 3d, 4d when the normal air supply system is defective. It is a braking device.

In this embodiment, the emergency braking device 8
In, the air delivery pressure is set in advance so that the BC pressures for all four axes are larger than the values in the conventional example by the ΔBC pressure.

Next, FIG. 2 is a timing chart showing the operation of the first embodiment of the present invention. In the figure, S11
Is a traveling forward command signal, and S12 is a traveling backward command signal. By inputting the signals S11, S12 to the control device 10, it is determined which of the axes 1, 2, 3, 4 is the front axis and which is the rear axis.

Further, in S15, in order to maintain the braking force applied to the front shaft in the present state, the control valve ("1e, 2
e "or" 3e, 4e ") to stop the air supply, while S17 is a similar air supply stop signal for the rear axle. S16 is a signal that causes the control valve of the front axle to expel air to loosen the braking force applied to the front axle, while S18 is a similar air expulsion signal for the rear axle, which has conventionally been used to re-drive wheels and rails. It is used for sticking. The control device 10 issues commands for these signals.

Further, S21 shows a change in BC pressure with respect to the front shaft, and S22 shows a change in BC pressure with respect to the rear shaft. The dotted line S20 shows the change in BC pressure in the conventional example, while S19 is the line monitoring the change in vehicle traveling speed.

Here, it is assumed that the axes 1 and 2 are determined to be the front axes and the axes 3 and 4 are determined to be the rear axes. Then, when the emergency brake command signal S13 is turned on, the emergency brake switching valve 7 is switched, and the air flows into the emergency brake device 8.
The air passes through the relay valve 6 and the control valves 1e, 2e, 3
Being flowed into e and 4e, BC pressure starts to rise rapidly.

At this time, regarding the front shaft, the supply stop signal S
By turning on 15 several times, a rapid rise to a predetermined BC pressure is prevented. This is to prevent gliding due to sudden rising. On the other hand, for the rear shaft, the supply stop signal S17 for the rear shaft is similarly turned on several times to prevent a sharp rise, and then the signal S17 is kept on.

Then, as shown by the front BC pressure change line S21, the reached BC pressure of the front shaft is the conventional BC pressure change line S.
BC that is larger than the reached BC pressure shown in 20 by ΔBC pressure
Kept under pressure. Further, as shown by the rear-axis BC pressure change line S22, the ultimate BC pressure of the rear-axis is the conventional BC pressure change line S
Contrary to the ultimate BC pressure shown by 20, the BC pressure is kept smaller by the ΔBCb pressure. That is, a larger braking force than before is applied to the front shaft, and a smaller braking force than before is applied to the rear shaft.

Next, FIG. 3 is a timing chart showing the operation of the second embodiment of the present invention. In the figure, signals corresponding to the respective signals in FIG. 2 are assigned the same reference numerals and explanations thereof are omitted. In this case, the difference from the first embodiment is that
The point is that after the supply stop signal S17 for the rear shaft is held in the ON state, the BC pressure of the rear shaft is gradually increased by finely repeating ON / OFF of the signal S17. Then, while monitoring the gliding detection signal S14 which is turned on when the gliding occurs, the BC pressure is maximized in the range where the gliding state is not reached. That is, it is possible to apply a braking force to the rear axle, which is more adhesive than the first embodiment.

Even with these methods, sufficient effects can be obtained as compared with the conventional methods. However, the magnitude of BC pressure on the rear axle is
Since it varies depending on the response time of the control valves 3d and 4d for the rear shaft, it is not guaranteed that the BC pressure is always optimum for the rear shaft. Therefore, an example in consideration of that point will be shown as a third example.

FIG. 4 is a timing chart showing the operation of the third embodiment of the present invention. Also in this figure, the signals corresponding to the signals in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted (the same applies hereinafter). In this case, the BC pressures of the front shaft and the rear shaft are input to the control device 10 and monitored. The time change of the BC pressure monitor value for the front axis is S
23, on the other hand, the time change of the BC pressure monitor value for the rear axis is shown in S24. That is, in the figure, the front-axis BC pressure monitor value S23 matches the front-axis BC pressure change value S21, while the rear-axis BC pressure monitor value S24 indicates the rear-axis BC pressure change value S2.
Draw a line that matches 2.

Then, the supply stop signal S17 for the rear shaft is maintained so that the BC pressure difference between the front shaft and the rear shaft is maintained at a predetermined value.
And the discharge signal S18 is controlled. This allows
The BC pressure of the rear shaft is always kept lower than the conventional BC pressure by a constant value.

Further, a fourth embodiment will be shown in which the equipment configuration is slightly changed to enable more accurate control. In this embodiment, a proportional valve is provided for each of the front shaft and the rear shaft. Then, the control unit 10 calculates the axial load movement amount during deceleration traveling as a function of deceleration. Then, the current value for controlling each proportional valve is set based on the calculated value. A slight increase in cost is required due to changes in the equipment configuration that accompanies the addition of proportional valves, but simpler control can be performed.

FIG. 5 is a timing chart showing the operation of the fourth embodiment. In the figure, S25 shows the change of the proportional valve control current value with respect to the front axis, while S26 shows the change of the proportional valve control current value with respect to the rear axis. The target value (A) of the control current S25 is set to be larger than the target value (B) of the control current S26.
As a result, the rear shaft BC pressure S22 is kept lower than the front shaft BC pressure S21 by a predetermined value.

In each of the above-described embodiments, the control may not be performed for each of the front axis and the rear axis, but may be controlled for each of the four axes.

As described above, according to this embodiment, the frequency of gliding can be clearly reduced, so that the number of times air is discharged for re-adhesion between the wheel and the rail is reduced. Therefore, it is possible to shorten the operating time of the compressor that sends out the high-pressure air and reduce the capacity of the air tank, which leads to cost reduction and vehicle weight reduction.

For the same reason, the life of the brake shoe pressed against the wheel can be extended.

Further, although the brake control is performed by the air pressure in this embodiment, hydraulic pressure may be used instead of the air pressure.

[0030]

As described above, according to the present invention, it is possible to obtain the brake control system which can shorten the braking distance while using the existing braking mechanism.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a vehicle according to an embodiment of the present invention.

FIG. 2 is a timing chart in the first embodiment of the present invention.

FIG. 3 is a timing chart in the second embodiment of the present invention.

FIG. 4 is a timing chart in the third embodiment of the present invention.

FIG. 5 is a timing chart in the fourth embodiment of the present invention.

[Explanation of symbols]

 1a, 2a, 3a, 4a Wheels 1e, 2e, 3e, 4e Control valve (adjustment means) 10 Control device (determination means)

Front Page Continuation (72) Inventor Kiyoshi Kawaguchi 38-8, Hikarimachi, Kokubunji, Tokyo 38 Railroad Technical Research Institute (72) Inventor Yasuhiro Takeuchi 100 Takegahana-cho, Ise City, Mie Prefecture Ise Manufacturing Co., Ltd. Within

Claims (1)

[Claims] 1. A brake control system used in a vehicle having a plurality of wheels and a brake for braking the wheels, the determining means determining a front-back relationship of the wheels with respect to a traveling direction when the vehicle is traveling, When the vehicle is decelerated by the braking operation of the vehicle, the braking force applied to the wheel determined to be the rear side by the determination means is smaller than the braking force applied to the wheel determined to be the front side by the determination means. A brake control system comprising: an adjusting unit for adjusting the brake.