JP2584429B2 - Fluid pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure control device which is used in an electromagnetic direct air brake device of a railway vehicle and controls a brake command and a Urme command.

[0002]

2. Description of the Related Art As a conventional example of a pneumatic brake device including such a fluid pressure control device, there is one shown in FIGS. 1 and 3 of Japanese Patent Application Laid-Open No. 63-162361, which is based on these. Is shown in FIG. 4 and described below. First,
The configuration will be described. In FIG. 4, a fluid pressure control device 1 includes a pressure sensor S, which is a fluid pressure / electric quantity converter, and first and second pressure sensors.
Comparators CO1 and CO2, first and second drive circuits DR1
And consists DR2, etc., first the feedback signal A ₂ from direct pipe SAP brake command signal A ₁ from the brake valve BV, second comparator CO1, and comparison operation with CO2, first, second driving circuit Urme solenoid valve RMV via DR1 and DR2
And the brake solenoid valve BMV is turned on and off. ON of the brake solenoid valve BMV and the Urme solenoid valve RMV,
By the off-control, air is supplied to the direct pipe SAP from the original air reservoir pipe MAP or exhausted to the atmosphere as appropriate.
, A desired pressure is generated, and the pressure is output to the brake cylinder BC via the relay valve RV. In order to stabilize the operation of the entire apparatus by providing a dead zone, a first set value α and a second set value β which are dead amounts are set in the first and second comparators CO1 and CO2, respectively. (However, α ≦ β)

Next, the operation will be described. FIG. 4 shows a state in which the brake valve BV is at the Urme position and the brake cylinder BC is exhausted. Brake command signal A ₁ in this state is 0, smaller deviation obtained by subtracting the feedback signal A ₂ from the command signals A ₁ (A ₁ -A ₂₎ is alpha. Therefore, the first
The comparator CO1 outputs a drive signal, and outputs the first drive circuit DR1
Excites the Urme solenoid valve RMV and opens it, and the direct pipe SAP communicates with the atmosphere. At this time, the second comparator C
O2 turns off the drive signal, and the second drive circuit DR2 demagnetizes and closes the brake solenoid valve BMV to close the direct pipe SAP.
Is shut off from the original air reservoir MAP.

In this state, the brake valve BV
The by operating the braking position, the brake command signal A ₁ is increased, the deviation between the feedback signal A ₂ (A ₁ -A ₂₎ exceeds the first set value α increases, the first comparator CO1 is driven The signal is turned off, and the first drive circuit DR1 outputs the Yurme solenoid valve RMV.
Is demagnetized to close the valve, and the direct pipe SAP is shut off from the atmosphere. At this time, the brake solenoid valve BMV remains closed. When the deviation (A ₁ −A ₂ ) further increases and reaches the second set value β, the second comparator CO2 outputs a drive signal, and the second drive circuit DR2 outputs the brake solenoid valve BM
V is excited to open the valve, and the original air reservoir MAP is connected to the direct pipe SAP.
The air is supplied from the controller and the vehicle enters the braking state. This direct pipe SAP
By the pressurization, the feedback signal A ₂ is increased, the deviation between the brake command signal A ₁ corresponding to the braking position (A ₁ -
When A ₂ ) decreases and becomes equal to or less than the second set value β, the second comparator CO2 turns off the drive signal, the second drive circuit DR2 demagnetizes and closes the brake solenoid valve BMV, and closes the direct pipe SAP. Pressurization stops. At this time, the Urme solenoid valve RMV is also kept closed, and is in the overlapping (brake holding) state.

In this overlapping state, the brake valve BV
The by operating the brake position of the low notch, the brake command signal A ₁ is reduced, the deviation between the feedback signal A ₂ (A ₁ -A
₂ ) becomes equal to or less than the first set value α, the first comparator CO1
Outputs a drive signal, the first drive circuit DR1 excites and opens the Urme solenoid valve RMV, and the direct pipe SAP is depressurized. At this time, the brake solenoid valve BMV remains closed. Due to the pressure reduction of the direct pipe SAP, the feedback signal A ₂
Decreases and the deviation from the brake command signal A ₁ (A ₁ −
When A ₂ ) increases and exceeds the first set value α, the first comparator CO1 turns off the drive signal, and the first drive circuit DR1 demagnetizes and closes the Yurme solenoid valve RMV to close the direct pipe. SAP
Decompression stops. At this time, the brake solenoid valve BMV remains closed, and is again in the same overlapping state as described above.

[0006]

As described above [0005] In conventional fluid pressure control apparatus, when the change rate of the brake command signal A ₁ is rapidly able to open and close once one of the solenoid valves of the brake or Loose a fluid pressure corresponding to the brake command signal a ₁ can be generated by. However, if the rate of change of the brake command signal A ₁ is kana loose, it is necessary to repeat the opening and closing of the solenoid valve. That is, in FIG. 5, when the required fluid pressure (brake command signal) PI ₁ starts continuously increases from 0, the fluid pressure (feedback signal) generated PO
_{In the case of 1} , the delay a is caused by the provision of the second set value β or the time lag of the operation of the solenoid valve or the like, and the brake solenoid valve starts rising at a constant speed after opening. When the generated fluid pressure PO ₁ catches up with the required fluid pressure PI ₁ , the brake solenoid valve closes and the generated fluid pressure P
The rise of O ₁ stops. (P _1). After repeating this and P _2, P _3. In this case, the required fluid pressure change rate is P
If it is small as I ₂ , the delay a and the generated fluid pressure PO ₂
Is constant due to the supply / discharge capacity inherent to the solenoid valve, so the number of times the solenoid valve is opened and closed increases. (P ₄ ~P _7). As described above, in the conventional fluid pressure control device, there is a problem that as the change speed of the brake command becomes slower, the number of operations of the solenoid valve increases, and the durability decreases due to wear and impact.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to increase the number of times the solenoid valve operates even if the speed of change of the brake command is slow. An object of the present invention is to provide a fluid pressure control device having improved durability without using the same.

[0008]

In order to solve the above-mentioned problems, a fluid pressure control device according to the present invention is a solenoid valve for supplying and discharging fluid by which a valve is opened and closed by a magnetic force of a solenoid against a biasing force of a spring to supply and discharge fluid. And a pressure sensor for feedback, and based on a difference between a control command input for instructing generation of a required fluid pressure and an input from the pressure sensor, drives the supply / discharge solenoid valve based on a difference between the fluid pressure according to the control command. A fluid pressure control device comprising a control circuit for generating the control command input; a change speed detection means for detecting a change speed of the control command input; a comparison detection means for comparing the change speed with a reference value; Setting means for selecting a coil current or a coil voltage of the supply / discharge solenoid valve based on the output.

[0009]

According to the above construction, the fluid pressure control device of the present invention sets the coil current or the coil voltage of the supply / discharge solenoid valve based on the output of the comparison detection means for detecting the change speed of the control command input. Here, the supply / discharge solenoid valve opens and closes the valve depending on the magnetic force of the solenoid and the biasing force of the spring opposing the solenoid to supply / discharge the fluid. Therefore, when the coil current or voltage of the solenoid valve is set to, for example, an intermediate value of the original set value, the valve stops at a position where the magnetic force of the solenoid and the biasing force of the spring are balanced, and the valve is opened and closed according to the magnetic force. The fluid supply / discharge speed according to the set value is obtained. The rate at which the generated fluid pressure rises or falls is proportional to the supply / discharge amount of the fluid. Therefore, when the control command input changes slowly, by setting the supply / discharge solenoid valve so as to reduce the fluid supply / discharge speed, the number of times of operation of the solenoid valve can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the fluid pressure control device of the present invention, FIG. 2 is a flowchart showing the operation of the fluid pressure control device of FIG. 1, and FIG. 3 is a diagram showing changes in fluid pressure. In FIG. 1, portions having the same functions as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

First, the configuration will be described. FIG. 1 is a block diagram showing the system of FIG. In FIG.
The difference from FIG. 4 is that the fluid pressure control device 4 includes a differentiating circuit DF as a change speed detecting means and a third circuit as a comparing and detecting means.
A comparator CO3 is provided, and a coil current setting unit DS is provided as a setting means in which a three-position solenoid valve MV integrating both the brake and the Yurme solenoid valve and a drive circuit DR thereof are used, and as setting means. Is a point. That is, a part of the brake command signal A ₁ is input to a differential circuit DF is a brake change rate detecting means, the fine fraction circuit DF by differentiating this changing speed signal A ₃ of the brake command to the third comparator CO3 Send out. The third comparator CO3 calculates the change speed A
₃ is compared with the set value γ, and whether the change speed A ₃ is larger than the set value γ is output to the coil current setting unit DS. The coil current setting unit DS includes a driving signal from the third comparator CO3,
A coil current is set based on the drive signals from the first and second comparators CO1 and CO2, and a set signal is output to the drive circuit DR. The drive circuit DR includes a PWM control unit, a transistor, and the like, and drives the three-position solenoid valve MV by changing the exciting current to a predetermined value based on the setting signal. Note that the first to third comparators CO1 to CO3 constitute a detection unit. Also,
Comparator CO0 indicated by a dotted line is used to detect the presence or absence of the brake command, when the brake command signal A ₁ is greater than the reference value, it intended to determine the presence of a brake command signal A _1, when it is determined that there is no Is for causing the coil current setting section DS to directly output the Urme command to the drive circuit DR.

Next, the operation will be described with reference to FIG. First, a case where the brake command signal is changed stepwise will be described. In FIG. 2, when the brake valve is in the Urme position, there is no brake command, and in accordance with the Urme command from the comparator CO0, the three-position solenoid valve is in the Urme position and the direct pipe communicates with the atmosphere (# 1, #). 7). In this Loose state, and operates the brake valve to the brake position, the braking command signal increases, the third comparator compares the change rate A ₃ of the brake command and the set value γ (# 2). If the change rate A ₃ of the set value or more γ (# 3~ # 5, # 7~ # 9)
Is the same as the conventional one, and the description is omitted. When the change rate A ₃ is less than the set value gamma, the drive signal from the third comparator is output to the coil current setting unit DS, the excitation current of the three-position solenoid valve is selected to slow feed and discharge position (# 11) . When the deviation (A ₁ −A ₂ ) between the brake command signal A ₁ and the feedback signal A ₂ is less than α, the first comparator outputs a drive signal, the three-position solenoid valve is in the Yurume position, and the direct pipe Communicates with the atmosphere (step # 17). Deviation between the brake command signal A ₁ is increased feedback signal A ₂ (A ₁ -A ₂₎ increases to reach the first set value alpha (Step # 12), the first comparator turns off the drive signal, The 3-position solenoid valve is in the overlapping position, and the direct pipe is shut off from both the atmosphere and the original air reservoir (step # 1).
6). Then, when the steam deviation (A ₁ −A ₂ ) further increases and reaches the second set value β (step # 13), the second comparator outputs a drive signal to the coil current setting unit DS and outputs the three-position solenoid valve. Is in a gentle braking position, and the direct pipe is supplied with air from the original air reservoir at a lower speed than usual, and a brake state is set (step # 14). The pressure of the direct tube, feedback signal A ₂ is increased, the deviation between the brake command signal A ₁ corresponding to the braking position (A ₁ -A ₂₎ becomes the second set value β decreases, the The two comparators turn off the drive signal, and the three-position solenoid valves are in the overlapping position (steps # 1, # 2, # 1).
1 to # 13, # 16), and the brake is held. Hereinafter, even when the brake valve is operated in the same manner as in the related art except that the exhaust is performed at a lower speed than usual, the description is omitted. The control is performed in the same manner as in the related art except that the supply and discharge are performed at the speed selected according to the changing speed of the command signal.

Next, a case where the brake command signal changes continuously will be described. In FIG. 3, PI ₃ is an increasing required fluid pressure (brake command signal A ₁ ),
PO ₃ indicates a fluid pressure (feedback command signal) generated at a normal air supply speed. Then, when the differentiating circuit detects the change speed, for example, the gradient A ₃ = b / a at the point 20 and compares it with the set value in the third comparator to select the slow supply speed, the generated fluid pressure becomes It rises a smaller rate than in the normal charge air speed as shown by curve PO _4, the number of operations of the solenoid valve is less than that of normal air supply rate _{(P 11, P 12) (} P 21, P ₂₂ ). The same applies to the case where the required fluid pressure is reduced, so that the description is omitted.

In the above case, the current is set to set the exciting current of the three-position solenoid valve, but the voltage may be set. Although the above description has been made on the case where the three-position solenoid valve is used, the case where the two-position solenoid valve is used is also described.
As described in the prior art, it is not essentially different,
The same can be applied.

[0015]

As described above, the fluid pressure control device according to the present invention includes a change speed detecting means for detecting a change speed of a control command input, a comparison detecting means for comparing the change speed with a reference value, and Since the setting means for setting the coil current or the coil voltage of the supply / discharge solenoid valve based on the output of the detection means is provided, the supply / discharge speed of the fluid according to the change speed of the control command input can be obtained. Therefore, when the speed of change of the control command input is slow, the number of times of operation of the solenoid valve can be reduced by setting the magnetic force of the solenoid valve for supply / discharge so as to reduce the supply / discharge speed of the fluid, thereby reducing wear. And impact resistance can be improved. In addition, since the supply / discharge amount of the solenoid valve is changed according to the change speed of the control command, overshoot and undershoot can be prevented when the change speed is slow, so that control is stabilized and control accuracy is improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a fluid pressure control device of the present invention.

FIG. 2 is a flowchart showing the operation of the fluid pressure control device of FIG. 1;

FIG. 3 is a diagram showing a change in fluid pressure of the fluid pressure control device of FIG. 1;

FIG. 4 is a schematic diagram showing a configuration of a conventional fluid pressure control device.

FIG. 5 is a diagram showing a change in fluid pressure of a conventional fluid pressure control device.

[Explanation of symbols]

A ₁ brake command signal (control command) A ₂ feedback signal (pressure input from the sensor) CO3 third comparator (comparator detecting means) DF differentiating circuit (changing speed detecting means) DS coil current setting unit (setting unit) MV 3 Position solenoid valve (supply / discharge solenoid valve) S Pressure sensor 3 Detector (control circuit) 4 Fluid pressure controller

Claims (1)

(57) [Claims] A supply / discharge solenoid valve for opening / closing a valve by a magnetic force of a solenoid that resists a spring urging force to supply / discharge fluid, a pressure sensor for feedback, and a control command input for commanding generation of a required fluid pressure. A fluid pressure control device comprising: a control circuit that drives the supply / discharge solenoid valve based on a difference from an input from the pressure sensor to generate fluid pressure in accordance with a control command.
A change speed detection means for detecting a change speed of the control command input, a comparison detection means for comparing the change speed with a reference value, and a coil current or a coil voltage of the supply / discharge solenoid valve based on an output of the comparison detection means. A fluid pressure control device, comprising: setting means for selecting.