JPS638061A - Controlling method for readhesion of wheel - Google Patents

Abstract

PURPOSE:To hasten readhesion without causing rerunning and restrain a braking distance after running to the minimum by feeding air to a brake cylinder in accordance with the recovered acceleration of an axle velocity when said axle velocity starts to be recovered. CONSTITUTION:At a time t1, when a third detecting circuit 10 detects running and its output becomes H, a solenoid valve driving circuit 9 turns on both solenoid valves MV1, MV2. Accordingly, air supply to a brake cylinder is stopped while air discharge is carried out and a BC pressure P is lowered relieving the braking force. When the progress of running is stopped at a time t2, since the output of the third detecting circuit 10 becomes L, the second solenoid valve MV2 is turned off, stopping the lowering of the BC pressure P. At the same time, an axle velocity V starts to be recovered and the output of a second detecting circuit 8 becomes H while a first detecting circuit 6 starts to detect the recovered acceleration velocity Valpha, and a selecting circuit outputs a pulse 2a or 2b, repeating the on-off of the solenoid valve MV1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wheel readhesion control method applied to an antiskid device that constitutes a part of an air brake control device for a railway vehicle.

[Conventional technology]

A conventional example of this type of control method is JP-A-54-1
There is something disclosed in Publication No. 59565, which is referred to as No. 4.
As shown in the figure. Further, a device for supplying and exhausting air to the brake cylinder according to this control method is shown in FIGS. 5 and 6.

In Figures 5 and 6, MVI is brake cylinder B.
MV2 is the second solenoid valve for exhausting air from brake cylinder BC, CC is the first solenoid valve for air supply to C, MV2 is the second solenoid valve for exhausting air from brake cylinder BC, and CC is the one that calculates the speed difference and acceleration/deceleration of each axle by manually measuring the speed of each axle. When skidding or recovery is detected, both the solenoid valves MVI and MV2
CV is a control valve that sends out pressurized air according to the brake command (not shown), RVI, RV
2 is a relay valve that amplifies the flow rate of the pressure air from the control valve CV, and MR is a pressure air source. In addition, relay valves RVI, R
Although V2 has a slightly different configuration, it is well known and will not be described in detail.

In both FIGS. 5 and 6, the control valve CV sends out air at a predetermined pressure in response to a certain brake command value, both solenoid valves y1vl and MV2 are off, and the relay valves RVI and RV
2 is a brake state in which pressurized air corresponding to the predetermined pressure is supplied to the brake cylinder BC and maintained. This braking state is shown in FIG. 4 up to time t1. In Fig. 4, ■ is the axle speed,
P is the air pressure of the brake cylinder BC (hereinafter abbreviated as BC pressure).

During this braking, if the axle speed ■ suddenly decreases from time t1 and the wheels slide, this is detected and both solenoid valves MVI
, MV2 are both turned on, and air supply to the brake cylinder BC is stopped and air is exhausted. As a result, the BCC pressure decreases and the brakes are braked.

When the sliding stops due to this drop and the axle speed begins to recover (at time t2), the second solenoid valve MV2 is turned off and exhaust is stopped, and the BCC pressure is maintained at the value at that time. . This exhaust time T is measured and stored, and is used for control described later.

Then, after the wheels have re-adhesive or at time t3, which is predicted to be when the re-adhesion is completed, the first solenoid valve MVl is turned off,
Supply air to the brake cylinder BC again. This air supply time is set to yXT (0<y<1).

Due to this air supply, the time t becomes y times the BCC pressure before the constant skiing.
4, turn on the first solenoid valve MVI again, and set the BC at that time.
The C pressure is held constant for a certain period of time, and at time t5, the first solenoid valve MVI is turned off and air is supplied to the brake cylinder BC.
At time t6, the original BCC pressure is restored.

That is, in the conventional re-adhesion control method described above, after skidding is detected,
Memorize the exhaust time T until the start of re-adhesion, supply air for y x T (however, 0 x 1) time from the end of re-adhesion to partially recover the BCC pressure, and return to the original state after a certain period of time. This is a method of restoring the BCC pressure to a constant state.

[Problem that the invention seeks to solve]

However, in the above conventional method, after detecting wheel slippage and exhausting the BC pressure, air supply is continued until re-adhesion is completed, and re-adhesion is completed when air starts to be supplied to the brake cylinder BC again. Since the brake force recovery control is not performed between time t2 and t3 in FIG. 4, even if the conditions of the rail surface and wheel tread are good and the recovery speed is high, this t2 The braking force is not restored between t3 and t3, and the braking distance is extended by that amount.

In addition, apart from the above conventional method, there is also a control method disclosed in Japanese Patent Publication No. 56-8776, but even in this second conventional method, various types of Calculations are performed in advance, and the speed at which the brake force is restored is changed based on the calculation results.In this case as well, air supply to the brake cylinder BC starts after readhesion is completed, so This method has the same problem as the conventional method No. 1.

[Means for solving problems]

Therefore, the present invention aims to minimize the extension of the braking distance while avoiding re-sliding after re-adhesion. , upon detecting wheel slippage based on a sudden drop in axle speed, exhaust the brake cylinder, and when the axle speed begins to recover due to the exhaust,
The air supply to the brake cylinder is gradually started, and the air supply speed is made slower as the recovery acceleration becomes smaller.

[Effect]

According to the above means of the present invention, when the axle speed starts to recover, air is supplied to the brake cylinder according to the recovery acceleration. However, when the recovery acceleration is small, the air supply speed is slowed down again. It is possible to accelerate readhesion without causing skidding, and it is possible to minimize the extension of the braking distance after skidding.

In other words, the recovery acceleration increases in proportion to the difference between the adhesion force and the braking force, so if the recovery acceleration is large, there is a margin in the braking force relative to the adhesion force, and the air supply speed is increased (to speed up the recovery of the brake force). ), it will not skid again, and conversely, if the recovery acceleration is small, the air supply speed will be lowered, so it will not skid again.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 3. Note that FIG. 1 shows an example of the control method of the present invention, FIG. 2 shows a first example of a control circuit for implementing this control method, and FIG. 3 shows a second example of the same control circuit.

First, FIG. 1 and FIG. 2 will be explained.

In FIG. 2, the first control circuit CCI gives commands to turn on and off the magnetic valves MVI and MV2 in both the devices shown in FIG. 5 or 6, and has the following configuration.

The oscillation circuit 1 generates a rectangular wave pulse, which is converted into two pulses 2a and 2b with different duty ratios by a duty pulse generation circuit 2 consisting of a counter circuit and a logic circuit.
This is transmitted to the selection circuit 3.

The selection circuit 3 also receives the recovery acceleration Vα from the first detection circuit 6, and this selection circuit 3 selects the pulse 2a when the recovery acceleration α is small, and selects the pulse 2a when the recovery acceleration Vα is large. 2b is selected and transmitted to the AND circuit 7.

Further, a signal based on the presence or absence of recovery detection is input from the second detection circuit 8 to the AND circuit 7, and is an "H" signal when recovery is detected, and an rLJ signal when no recovery is detected. The output of this AND circuit 7 is transmitted as 1 to the magnetic valve drive circuit 9.

A signal based on the presence or absence of skidding progress detection is input from the third detection circuit 10 to the electromagnetic valve drive circuit 9.
When the skidding progress detection signal rHJ is input, it is given priority to both solenoid valves MVI.

When MV2 is turned on and the non-detection signal rLJ is input, the second solenoid valve MV2 is turned off and the AND circuit 7 is turned on.
The first solenoid valve MVl is controlled to be turned on or off based on the output of the first solenoid valve MVl.

In Fig. 1, ■ is the axle speed, P is the air pressure (BC pressure) of the brake cylinder BC, and up to time t1, the BC
C20 indicates that the brake is being operated while being maintained at a predetermined pressure. At this time, in the control circuit CCI, since the first detection circuit 6 cannot detect the recovery acceleration Vα, the output of the selection circuit 3 is "L", the output of the AND circuit 7 is also rLJ, and no skidding has occurred. Therefore, the output of the third detection circuit IO is also rLJ. Therefore, both magnetic valves MV1. M2 is off (see Figures 5 and 6).

At time t1, when the third detection circuit 10 detects skidding and its output becomes rHJ, the solenoid valve drive circuit 9 activates both solenoid valves MVI.
, turn on MV2. Therefore, brake cylinder B
Air supply to C is stopped and exhaust is performed, and BCC
It drops by 20 and gets dumped. This state continues until time t2 when the progress of sliding stops.

When the progress of skiing stops at time t2, the third detection circuit 10
Since the output becomes rLJ, the second solenoid valve MV2 is turned off and BC exhaust is stopped, and the decrease in BCC20 is stopped. At the same time, the axle speed V begins to recover, and the output of the second detection circuit 8 becomes r
Since the first detection circuit 6 starts detecting the recovery acceleration Vα at the same time as HJ, the selection circuit 3 selects the pulse 2a or 2.
b is transmitted to the electromagnetic valve drive circuit 9 via the AND circuit 7, and the first electromagnetic valve MVI is repeatedly turned on and off.

In the example of FIG. 1, since the recovery acceleration ■α is small between times t2 and t3, the selection circuit 3 selectively outputs the pulse 2a, and based on this, the air supply time is determined to be the air supply stop time. It is shorter than , and BCC20 rises at a slow rate. Furthermore, between times t3 and t4, since the recovery acceleration Vα is large, the selection circuit 3 selectively outputs pulse 2b, and based on this, the air supply time is longer than the air supply stop time. , BCC20 rises quickly. That is,
When the axle speed ■ starts to recover, the BCC20 is gradually increased by periodically repeating BC air supply and its stop, and the air supply time in one cycle is made shorter as the recovery acceleration Vα becomes smaller.

Then, at time t4, re-adhesion is completed and BCC20
Return to original value. After this, the first electric valve MVI also continues to be off.

In the first control circuit CCI, the number of pulses selected depending on the magnitude of the recovery acceleration α is two, but the number may be three or more.

Further, the second control circuit CC2 shown in FIG.
This is an example in which a reference pulse generation circuit 4 and a comparison circuit 5 are used in place of the oscillation circuit 1° duty pulse generation circuit 21 selection circuit 3 in the control circuit CCI.

The reference pulse generation circuit 4 outputs a biased triangular wave pulse, which is compared with the recovery acceleration Vα in the comparison circuit 5, and pulses having continuously different duty ratios are transmitted to the AND circuit 7 depending on the magnitude relationship.

In the case of this second control circuit CC2, the recovery acceleration Vα
is less than the bias value of the triangular wave pulse, the output of the comparison circuit 5 holds rHJ, and the second detection circuit 8 outputs the recovery detection signal rHJ, so the AND circuit 7
The output also maintains rHJ, the drive circuit 9 keeps the first solenoid valve MVI on, and the BC air supply continues to be stopped. That is, if the recovery acceleration Vα is less than the very small lower limit setting value ■α1, air will not be supplied to the BC.

When the recovery acceleration ■α exceeds the lower limit setting value ■α1, the first electromagnetic valve MVI periodically repeats on and off based on pulses with different duty ratios as compared with triangular wave pulses. Also in this case, the smaller the recovery acceleration Vα, the shorter the air supply time in one cycle.

Then, when the recovery acceleration ■α exceeds the upper limit setting value 172, the output of the comparator circuit 5 becomes rLJ, so even if the second detection circuit 8 outputs the recovery detection signal rHJ, the output of the AND circuit 7 becomes “ "L", the first solenoid valve MVI is turned off, and air is continuously supplied to BC.

That is, also in the case of the second control circuit CC2, the air supply is controlled according to the magnitude of the recovery acceleration Vα, and moreover, the smaller the recovery acceleration Vα is, the slower the air supply speed is.

In the second control circuit CC2 of FIG. 3, the bias of the triangular wave pulse may be eliminated, or ■α1
The range of <Vα<■α2 may be controlled by dividing it into a plurality of parts instead of continuously.

Furthermore, in the first control circuit CCI in FIG. 2, the lower limit setting value V in the second control circuit CC2 in FIG.
α1. The same setting as the upper limit setting value Vα2 may be performed.

〔effect〕

As explained above, according to the readhesion control method of the present invention,
When the axle speed begins to recover due to the exhaust of the brake cylinder after skidding, air is gradually supplied to the brake cylinder according to the magnitude of the recovery acceleration, and the smaller the recovery acceleration, the slower the air supply speed is. In other words, since the braking force is restored according to the speed while the re-adhesion is progressing, the braking distance can be shortened compared to the conventional method of recovering the braking force after the re-adhesion is completed, and even if a -4 skid occurs. This can minimize the extension of the braking distance.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the method of the present invention, Fig. 2 is a first control circuit diagram for carrying out the method of the present invention, Fig. 3 is a second control circuit diagram of the same, and Fig. 4 is a conventional control circuit diagram. An explanatory diagram of the method, FIG. 5 shows a first example of an air supply and exhaust system for the brake cylinder BC, and FIG. 6 shows a second example of the air supply and exhaust system for the brake cylinder BC. ■...Axle, speed Vα...Recovery acceleration MVI...
・First solenoid valve MV2...Second solenoid valve RVI, RV2
...Relay valve BC...Brake cylinder

Claims (1)

[Claims] (1) When braking while supplying air to the brake cylinder,
When wheel skidding is detected based on a sudden drop in axle speed, the brake cylinder is evacuated, and when the axle speed begins to recover due to the exhaust, air is gradually supplied to the brake cylinder, and the air supply is A wheel readhesion control method characterized in that the smaller the recovery acceleration, the slower the speed.