JPS5983502A - Readhesion accelerator for vehicle - Google Patents

Abstract

PURPOSE:To enable to suppress the slip of a vehicle to a sufficiently low value due to the reduction of a drive force of the minimum necessary limit, by suitably cooperating a slip preventive brake and a notch return in response to the slipping state. CONSTITUTION:A comparator 3 detects a slipping speed from the speed difference between a reference tachometer generator 1 and the tachometer generator 2 of a driving axle, and a differentiator 4 differentiates the output of the generator 2 to detect the acceleration. Comparison amplifiers 5, 6 respectively compare the slipping speed and the acceleration with set values 5a, 5b, and respectively apply the slip detection signals to solenoid valves 12, 13 in a slip brake 10 through an OR circuit composed of diodes 7, 8. On the other hand, the output of the comparator 3 for detecting the slipping speed is also applied to a comparison amplifier 18 to output a notch return command N when exceeding a set value 18a, thereby sequentially reducing the drive force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a slip readhesion promoting device for a vehicle, and more particularly to a high performance slip readhesion promoting device that uses both a slip preventing brake and a notch return function.

[Prior art]

Improving adhesive performance is an important issue in achieving mass transportation, which is one of the major missions of railway vehicles. For this reason, research and development has been carried out by many researchers for a long time, and there are many documents. Furthermore, it is essential to improve adhesive performance in order to save energy, and various measures to improve adhesive performance are currently being proposed.

Among these, the so-called slip prevention brake, which detects the slip of the driving wheels and quickly applies the air brake to the wheels to suppress the slip, has a small drop in driving force as the speed increases, and the slip speed is relatively high. This method is effective as a slip readhesion promoting device for DC and AC/DC vehicles, electric diesel locomotives, etc. that are easy to move. However, if the adhesion conditions are very poor, such as when the adhesion coefficient between the rail and the wheel is extremely low, the idling shaft cannot be sufficiently re-adhered.

For this reason, a method has been proposed in which notch return control is added to the slip prevention brake to reduce the driving force and suppress slip.
Methods have been put into practical use that include 1) operating both at the same time, or (11) providing a delay between the operation times of the anti-slip brake and notch return, and performing notch return if the notch does not re-stick after a predetermined period of time has elapsed. .

However, in the above-mentioned conventional technology, in case (1), the driving force is reduced more than necessary even in a slipping state where the anti-slip brake can sufficiently re-stick, and in case (11), the acceleration of slipping is reduced. It reached a large idle speed before the notch could be returned significantly, and unless the notch was returned to the dog riJ, it would not stick again, resulting in an extremely low driving force. For this reason, there were drawbacks such as damage to the rails and wheel treads if the wheels were to spin too much.

It is also possible to increase the braking force of the anti-slip brake so that it can re-adhere even in any slipping condition, but a large braking force is applied even in the slightest slipping, resulting in a significant drop in driving force. , it also has an adverse effect on the strength of the brake device.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a re-adhesion promoting device for a vehicle that can quickly suppress slippage in view of the above-mentioned drawbacks of the prior art.

[Summary of the invention]

The present invention detects the slip speed of the driving wheels, sets two set values for this detection output, issues a slip prevention brake command when the detected output exceeds one set value, and issues a slip prevention brake command when the detected output exceeds the other set value. When this occurs, issue a command to return the notch.
In the case of a small slip, the slip is suppressed by using only the slip prevention brake, and when the slip is in a state where the slip prevention brake is capable of re-sticking, the slip return is operated.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 4.

FIGS. 1 and 2 are diagrams used to explain the slipping phenomenon.

Figure 1 shows the sliding adhesion coefficient μS1 between the wheels and rails, the adhesion tensile force μSW, and the driving torque F for the idle speed ■8.
represents the characteristics of (However, it is assumed that the driving force F is constant with respect to the idling speed ■6.) The driving wheels start idling at the point Fg, but since the driving torque F exceeds the adhesive tensile force μsW, they continue to accelerate further. , it becomes a big flop. If the force accelerating the idling shaft at this time is Fg, then Fi = F-μ
It is represented by SW and corresponds to the shaded area in the figure. At the position of the idling speed vIIl, the acceleration force Fg occupies about half of the driving force.

Therefore, a method is used to reduce the force Fm that accelerates the idling shaft by applying an air brake to the idling shaft or the driving wheels of the bogie, but if this braking force is not greater than the acceleration force FII of the idling shaft, the idling driving wheels will decelerate and re-stick. I can't.

This state will be explained in more detail with reference to FIG.

First, the coefficient of friction f between the wheels and cast iron brake shoes is calculated using the experimental formula used by Japanese National Railways, etc., and the result is as shown by the broken line in Figure 1. Now, if the pressing force of the brake cylinder is P, the brake force is expressed as f-p.

Therefore, the force acting on the idling shaft with respect to the idling speed Vi is the force that accelerates the idling shaft Fg=F−μSW as described above.
The brake force f−p is the difference between the two, Fsn=Fi
r-p is the force that accelerates the slipping shaft when the slipping prevention brake is activated. Figure 2 shows these.

In the figure, the point where the force Fsn that accelerates the slipping shaft when the slipping prevention brake is activated is zero, that is, while the slipping shaft is spinning,
The idle speed when the vehicle is moving at a constant speed is Vs2
Then, when Vs<Vgz, FIIB is 0, so the slip is decelerated only by the slip prevention brake, and the driving wheels re-stick.

However, when VB2<V[+, FllB>0, the slip is further accelerated and the driving wheels cannot be made to stick again.

FIG. 3 is a block diagram showing one embodiment of the present invention, where l is a reference shaft speed generator signal, generally generated by the speed generators of all moving shafts connected in series. For example, the minimum moving shaft speed among them may be used as the reference shaft speed signal. 2 is one of the speed generator signals of the moving shafts connected in series. Therefore, the apparatus shown in FIG. 3 is used for one moving shaft. 3 is a comparator that detects the idling speed from the speed difference between the speed generators 1 and 2; 4 is a differentiator that detects acceleration; and 5 and 6 are idling speeds that are compared with set values 5a and 6a of the idling speed and acceleration, respectively. Comparison amplifiers 7 and 8 that generate the signal are double diodes that form an OR circuit between the slip detection signal based on the slip speed and the slip detection signal based on the acceleration. However, it is configured to quickly detect idling. In this way, the speed difference of each axis, that is, the idling speed and acceleration, are set to 5a.
, 5a, which generates a slip detection signal is collectively referred to as a slip detection device 9. In addition, based on the output signal of the slip detection device 9, the solenoid valves 12 and 13 in the slip prevention brake 10 are operated (12 is an ON solenoid valve, 13 is an OFF solenoid valve), and the source air reservoir (not shown) and the auxiliary tank 11 are operated. The air is sent via a double check valve 16 to the brake 7 cylinder 17, which is piped to each idling shaft or each bogie, and applies an air brake to the idling shaft to make it stick again. In addition, 14 and 15 are a safety valve and an air pressure switch to detect and protect the abnormal pressure of the anti-slip brake 10.In addition to the double reverse valve 16, a normal vehicle stop brake is connected to a brake valve (not shown) from the inlet of the brake valve (not shown). Air is sent to the brake cylinder 17 via the brake cylinder 17.

Further, the output of the slip detection device 9 is used not only to operate the slip prevention brake 10, but also as an operation signal when combined with other readhesion promoting devices such as a notch stopper or automatic sand scattering. It is important to quickly detect the output of this slip detection device it9 at a slip speed as low as possible and to issue a signal in order to improve re-adhesion.

On the other hand, the output of the comparator 3 that detects the idling speed is also guided to a separately provided comparison amplifier 18, and is compared with a set value 18a, and when the set value 18a is exceeded, a notch return command N is issued and the main circuit (Fig. (not shown) to sequentially reduce the driving force.

Comparison amplifier 1 for generating notch return command N
8 set value 18a and a comparison amplifier 5 for generating an anti-slip brake command to operate the anti-slip brake 10.
, 6 is set to operate at a slipping speed different from the set values 5a and 6a of the slipping prevention brake 10, and the notch return is performed only in the slipping state in which the slipping prevention brake 10 cannot re-adhesion.

In addition, as shown in Fig. 2, the slip speed (that is, slip detection sensitivity) generated by the notch return command Nt is determined by the combination of the force Fs (=F-μs W) that accelerates slip and the braking force f-p of the slip prevention brake. It is best to set it near the joint speed (VB2 in Figure 2). However, in reality, the slip adhesion coefficient μS between the wheel and rail and the friction coefficient f between the wheel and brake shoes tend to vary considerably, and the idling speed at which the force accelerating the idling shaft becomes zero also changes. In experiments, we quickly detected when the wheels were idling, activated the idling prevention brake, and returned the notch at a idling speed of around lQ km/h, thereby increasing the maximum idling speed to approximately 15 km/h.
I was able to keep it down to around /h.

FIG. 4 is an example of an actually measured slipping phenomenon to explain the present invention in detail. , [:I] has relatively good adhesion state improvement, idling speed V11 and idling acceleration dVII/4t (
Not shown. ) is low. First, idling occurs at point 31, idling is detected at point bI, and a idling prevention brake command is output. The slip prevention brake is activated by this slip prevention brake command, and the notch is re-adhesed at point Cs without outputting the notch return command N. In this case, the drop in traction force P was very small, dropping to about 92 inches at the start of idling, but quickly returning to its original level.

On the other hand, U-th is a case where the adhesion condition is relatively poor and the slipping becomes thick. In this case as well, idling occurred at 32 points,
Idling is detected at point b2 and the anti-slip brake is activated.

However, this is not suppressed and the idling speed VI+ continues to increase, so a notch return command N is issued at point α, causing the armature current I to increase.

is rapidly reduced. As a result, the traction force P of the driving wheels
is suppressed, leading to re-adhesion. In this case, since the notch was returned at an appropriate idling speed, a large idling did not occur, and the traction force decreased to approximately 78% of the value immediately before the idling, but it is about to return to its original value.

As mentioned above, the slip prevention brake and notch return function should be operated appropriately depending on the slipping condition, and the notch return should not be performed when the slip prevention brake can be used to re-adhere with only the slip prevention brake alone. I quickly returned the notch. In this way, the following effects will appear, instead of just reducing the necessary minimum driving force to suppress idling.

(1) Increase in idling speed is suppressed, reducing wear and tear on wheels and rail surfaces.

(2) Since the braking force of the anti-slip brake is strengthened, there is no need to increase the brake cylinder pressure, and the re-adhesion effect is good with the same braking force as the V-key that stops the vehicle.
The reliability of the brake equipment is improved.

In addition, the measurement results shown in Figure 4 show that the slipping prevention brake command and the notch return command N differ in the slipping speed during operation, and in the past, the above operation command was released until the notch was completely re-adhered. However, the release of the above signal also had a hysteresis, which made it possible to re-stick with only the slip prevention brake.At the slip speed (point β), the notch returned to the direction of stickiness even without the slip prevention brake. Speed (CI+ 02
The anti-slip brake is released at point ), which has the effect of further minimizing the reduction in driving force.

Furthermore, in the embodiment shown in FIG. 3, the signal for the notch return command N is compared and amplified based on the output of the comparator 3 that detects the speed difference in the slip detection device 9, but the comparator 3 is used separately. Even if a completely different idling detection device and shaft speed detection are performed, the effect remains the same.

〔Effect of the invention〕

As described in detail above, according to the present invention, the slip prevention brake and the notch return can be appropriately used in combination depending on the slip state, so that the slip can be suppressed to a sufficiently low value by reducing the necessary minimum driving force.

[Brief explanation of drawings]

1 and 2 are characteristic diagrams used to explain the slipping phenomenon, FIG. 3 is a configuration diagram showing an embodiment of the present invention, and FIG. 4 is a diagram illustrating the actually measured operation of the present invention. 1... Reference shaft speed generator signal, 2... Speed generator signal, 3... Comparator for detecting idling speed, 4... Differentiator, 5... Comparison amplifier (idling speed ), 5a... Idle speed setting value, 6... Comparison amplifier (for idle acceleration),
6 a'...Acceleration setting value, 9...Slip detection device,
10... Idling prevention brake, 18... Comparison amplifier for notch return command, 18a... Setting value for notch return command, L... Idling prevention command, N... Notch return command, F
[IB... Force to accelerate the slipping shaft when the slip prevention brake V-key is activated, f-p... Brake force.

Claims (1)

[Scope of Claims] 1. A means for generating a slip detection signal according to the slip speed of the driving wheels in a device that suppresses the slip of the driving wheels of a vehicle by using a slip prevention brake and notch return, and a means for generating a slip detection signal according to the slip speed of the driving wheels; There are two set values for the slip detection signal, and a means for issuing a slip prevention brake command when the slip detection signal reaches one set value or more, and a means for issuing a notch return command when the slip detection signal reaches the other set value or more. A vehicle readhesion promoting device characterized by: 2. The readhesion promoting device for a vehicle according to claim 1, wherein the means for detecting the slipping is determined as the slipping speed by comparing the reference speed of the moving shaft and the speed of the slipping shaft. 3. The re-adhesion promoting device for a vehicle according to claim 1 or 2, wherein the set value of the notch return command is larger than the set value of the slip prevention brake command. 4. In claim 3, the setting value of the notch return operation command is an idling speed at which the idling acceleration force that attempts to accelerate the idling shaft and the braking force of the idling prevention brake are in balance. A vehicle re-adhesion promoting device characterized by: