JPH10147235A - Fluid pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve response characteristic as well as durability and reliability. SOLUTION: A three-position electromagnetic valve 61 to which fluid pressure commands are given is switched to a supply position, an exhaust position and an overlap position to generate output pressure. The output pressure generated by the valve 61 is fedback to a controller 65. The controller 65 compares a fluid pressure command value with a feedback signal value for the output pressure to control the valve 61 to be witched to a position corresponding to its difference. At this time, the controller 65 judges that the output pressure exists in a slow position control zone set outside the pressure tolerance of the fluid pressure command value to output a slow supply command value on condition that the fluid pressure command value is greater than the output pressure and judges that the output pressure exists in the slow position control zone to output a slow exhaust command value on condition that the fluid pressure command value is smaller than the output pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a supply, overlapping,
The present invention relates to a fluid pressure control device that performs switching control of a three-position solenoid valve that takes each position of exhaust by giving a fluid pressure command, and for example, relates to a fluid pressure control device that is applied to a brake device of a railway vehicle.

[0002]

2. Description of the Related Art Conventionally, brake devices for railway vehicles include:
A device using air pressure is applied. This type of device is configured, for example, to output an output pressure using an electromagnetic valve, amplify the output pressure to a brake pressure by a relay valve, and operate the brake cylinder by the brake pressure. Solenoid valves for generating output pressure include:
For example, a three-position solenoid valve having a first port connected to the atmosphere, a second port connected to the supply air reservoir, and a third port connected to the relay valve is applied. That is, this 3
The position solenoid valve communicates the first port with the third port to exhaust air from the relay valve, and communicates the second port with the third port to relay compressed air from the supply air reservoir. A supply position for supplying the valve and an overlapping (lap) position for maintaining the output pressure by closing all the first, second and third ports can be taken. Such 3
Details of the configuration of the position solenoid valve are described in Japanese Utility Model Publication No. 7-31020.

[0003] By operating a brake controller provided in the driver's cab of a railway vehicle, for example, from the 0th stage to the 7th stage
It is possible to output a total of eight stages of brake commands up to the stage. Based on the brake command, the solenoid valve control device generates three levels of exciting currents for controlling the three-position solenoid valve to the exhaust position, the supply position, or the overlap position.
If the required exciting current is different between when shifting from the supply position to the overlapping position and when shifting from the exhaust position to the overlapping position, the exciting current corresponding to the overlapping position is set in two stages. In this case, a total of four levels of exciting current can be input to the three-position solenoid valve.

[0004]

However, in the above-described configuration in which the three-position solenoid valve is controlled by the three-step or four-step excitation current, the occurrence of overshoot or undershoot cannot be avoided. Therefore, it takes time until the output pressure output from the three-position solenoid valve converges to the brake command pressure, and as a result, there is a problem that the response until the expected brake pressure is obtained is not necessarily good.

Further, when overshoot or undershoot occurs, the position of the three-position solenoid valve must be frequently switched before the output pressure converges to the brake command pressure. May become unstable. Therefore, if the above-mentioned problems of overshoot and undershoot can be overcome, it is considered that the braking characteristics of the railway vehicle are improved and the life of the brake device is also extended.

Japanese Patent Application Laid-Open No. Hei 6-171497 discloses that a gentle supply position is set between the supply position and the overlap position of the three-position solenoid valve in order to prevent the above-mentioned overshoot or undershoot. In addition, there is disclosed an apparatus in which a gentle exhaust position is set between an exhaust position and an overlap position, and a current value of five stages corresponding to each position is set to control an output pressure. However, since the fluid pressure command takes the gentle supply position or the gentle exhaust position under the condition that the change speed of the fluid pressure command is smaller than the reference value, the fluid pressure command is changed at a large change speed. If the predetermined value is set immediately thereafter, the three-position solenoid valve switches to the slow supply position or the slow exhaust position in a state where the output pressure does not follow the target pressure, and there is a problem that the response to the target pressure is deteriorated. Was.

In view of the above technical problems, an object of the present invention is to provide a fluid pressure control device capable of improving response characteristics by improving control of a three-position solenoid valve for outputting output pressure. It is. It is another object of the present invention to provide a fluid pressure control device having improved durability and reliability.

[0008]

According to a first aspect of the present invention, there is provided an apparatus for controlling a fuel supply system, comprising the steps of selectively switching a supply position, an exhaust position and an overlapping position in response to a fluid pressure command. A three-position solenoid valve that generates pressure, and a control unit that controls the switching of the three-position solenoid valve to a position where the difference is matched by comparing the fluid pressure command value and the feedback signal value of the output pressure. The unit is a value between a supply command value that sets the three-position solenoid valve as the supply position and an overlap command value that sets the overlap position, and a slow supply command value that sets the three-position solenoid valve as a slow supply position; A storage means for storing a slow exhaust command value for setting the three-position solenoid valve to the slow exhaust position, the storage means for storing a value between the exhaust command value for setting the three-position solenoid valve to the exhaust position and an overlap command value; Is the output pressure at the fluid pressure command value. It is determined that it exists in the gentle position control zone set outside the force tolerance, and is stored in the storage means on condition that the command pressure corresponding to the fluid pressure command value is larger than the output pressure. A gradual supply command value is output, and it is determined that the output pressure exists in the gradual position control zone, and on the condition that the command pressure is smaller than the output pressure, the gradual exhaust command value stored in the storage means is used. And a command control means for outputting.

According to the fluid pressure control device having the above-described structure, the three-position solenoid valve receives the fluid pressure command and selectively switches between the supply position, the exhaust position, and the overlap position, thereby generating an output pressure. The output pressure generated from the three-position solenoid valve is fed back to the control unit. The control unit compares the fluid pressure command value with the feedback signal value of the output pressure, and controls switching of the three-position solenoid valve to a position where the difference is matched.

At this time, the command control means of the control section determines that the output pressure exists in the gentle position control zone set outside the pressure tolerance of the output pressure in the above-mentioned fluid pressure command value, and the command pressure is determined. On condition that the output pressure is higher than the output pressure, the slow supply command value stored in the storage means is output, it is determined that the output pressure exists in the slow position control zone, and the command pressure is lower than the output pressure. Is output, the slow exhaust command value stored in the storage means is output.

The slow supply command value stored in the storage means is set to a value between a supply command value for setting the supply position of the three-position solenoid valve and an overlap command value for setting the overlap position. The command value is set to a value between the exhaust command value at which the three-position solenoid valve is set to the exhaust position and the overlap command value.
Thereby, when the output pressure is in the slow position control zone and the command pressure is larger than the output pressure, the three-position solenoid valve is set to the slow supply position between the supply position and the overlap position,
Fluid supply can be made gradual. If the output pressure is in the gentle position control zone and the command pressure is smaller than the output pressure, the three-position solenoid valve is set to the gentle exhaust position between the exhaust position and the overlapping position, Can be gently exhausted. For this reason, overshoot and undershoot of the fluid pressure can be suppressed or prevented. As a result, the response characteristics of the three-position solenoid valve can be improved. In addition, since the three-position solenoid valve can be prevented from being frequently switched, the durability and reliability of the three-position solenoid valve can be improved.

According to a second aspect of the present invention, in the fluid pressure control apparatus according to the first aspect, the command control means includes an output pressure in a gentle position control band and a rate of change of the output pressure as an absolute value. When it is determined that it is smaller than the reference change rate,
Output means for outputting a gently supplying command or a gently exhausting command, and outputting an overlapping command when it is determined that the output pressure is in the gradual position control zone and the rate of change is greater than the reference rate of change as an absolute value. This output means outputs the slow supply command value stored in the storage means on condition that the output pressure is smaller than the command pressure, and on condition that the output pressure is larger than the command pressure, The slow exhaust command value stored in the storage means is output.

According to this configuration, the output means outputs the slow supply command or the slow exhaust command when the output pressure is in the slow position control zone and the absolute value of the change rate is smaller than the reference change rate. When the output pressure is present in the slow position control band and the absolute value of the change rate is greater than the reference change rate, a weight command is output, but the output pressure is present in the slow position control band, and When the absolute value of the change rate is smaller than the reference change rate, the magnitude relationship between the command pressure and the output pressure indicates
It is determined whether to output the slow supply command or the slow exhaust command.

As described above, the output means outputs the overlap command when the output pressure is in the gentle position control zone and the rate of change is greater than the reference change rate as an absolute value. When approaching the command pressure rapidly, 3
The position solenoid valve can be set to the overlapping position immediately from the supply position without setting to the gentle exhaust position or the gentle supply position. For this reason, overshoot and undershoot can be suppressed or prevented more effectively.

According to a third aspect of the present invention, in the fluid pressure control device according to the first or second aspect, the command control means is configured to control the slow supply command value or the slow exhaust command value stored in the storage means for a predetermined time. On condition that the continuation is performed, the supply command value or the exhaust command value is output, respectively.

According to the above configuration, when the slow supply command value or the slow exhaust command value continues for a prescribed time, the fluid pressure command value for setting the three-position solenoid valve to the supply position or the exhaust position is output.
Even if the three-position solenoid valve is slowly supplied and slowly exhausted, this can be guaranteed when the output pressure does not converge within the pressure tolerance due to slight air leakage or malfunction of the solenoid valve.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the fluid pressure control device of the present invention will be described in detail. FIG. 6 is a block diagram conceptually showing a configuration of a railway vehicle brake control device to which an embodiment of the present invention is applied, and shows a configuration for one vehicle. One vehicle is provided with two trolleys 1 and 2. Each of the carts 1 and 2 has a pair of axles 11 and
12; 21 and 22 are provided, and wheels are fixed to both ends of each axle. B associated with each axle, pneumatically actuated brake cylinders BC11, BC12; B
C21 and BC22 are provided. Each of the brake pressures is applied to a pair of brake cylinders provided on one truck by the brake pressure output devices 15, 25, 35, and 4.
5 to give.

The brake pressure output devices 15, 25, 35,
The brake pressure output by 45 is a service brake command or an emergency brake command by operating a brake controller provided in a train cab, a rotation speed signal of each axle detected by a vehicle speed sensor (not shown), and a vehicle or a bogie. Is controlled based on the output signal of the adaptive loader 51 which detects the load of the load.
More specifically, the service brake command, the emergency brake command, and the output signal of the response load device 51 are transmitted to the brake control unit 5.
0 is input to the brake pattern unit 52. The brake pattern unit 52 calculates a fluid pressure command value for performing service brake control and emergency brake control for each axle based on the input signal, and outputs the brake pressure output devices 15 and 2.
5, 35 and 45 are output individually. Further, a speed signal from the vehicle speed sensor is input to a slide control unit 53 for preventing wheels from slipping on the rail. The sliding control unit 53 calculates and outputs a fluid pressure command value for performing the sliding control for each of the brake pressure output devices 15, 25, 35, and 45.

The brake pressure output devices 15, 25, 35,
45 are brake cylinders BC11, BC12; BC21, BC21 based on a fluid pressure command from the brake control unit 50.
Supply BC22 with the appropriate brake pressure. FIG. 7 is a simplified block diagram showing a configuration of the brake pressure output device 15 corresponding to the axle 11. The remaining brake pressure output devices 25, 35, and 45 have the same configuration.

Referring to FIG. 1, brake pressure output device 1
5 is a relay valve 60 for supplying a brake pressure to the brake cylinder BC11, and a fluid pressure control device 1 of the present invention.
The fluid pressure control device 10 calculates and outputs a three-position solenoid valve 61 that supplies an output pressure to the relay valve 60 and a drive current for driving the three-position solenoid valve 61. And a control unit 65. The control unit 65, the fluid pressure command value P _ACO is inputted from the brake control unit 50.
Further, an output pressure sensor 64 for detecting an output pressure (AC pressure) output from the three-position solenoid valve 61 is provided in connection with the three-position solenoid valve 61. The output pressure signal from the output pressure sensor 64 is amplified by the amplifier 67 and fed back to the control unit 65. Control unit 6
5 samples the output pressure signal from the output pressure sensor 64 every predetermined sampling period (for example, 5 milliseconds). The control unit 65 may be configured in the brake control unit 50.

The three-position solenoid valve 61 is conventionally known, and has a configuration as disclosed in, for example, Japanese Utility Model Publication No. Hei 7-31020. That is, the three-position solenoid valve 61
Is a first port P1 connected to the atmosphere and a supply air reservoir 7
It has a second port P2 connected to 0 and a third port P3 connected to the pressure chamber 60a of the relay valve 60. The air pressure output from the third port P3 is the output pressure, and the output pressure is monitored by the output pressure sensor 64 as described above. The three-position solenoid valve 61 is driven by a current supplied from the control unit 65, and can selectively take three basic positions of a discharge position, a supply position, and an overlap (lap) position. At the discharge position, the first port P1 and the third port P3 communicate with each other, and the output pressure decreases. At the supply position, the second port P2 communicates with the third port P3, and the output pressure increases. In the overlapping position, the first,
The second and third ports P1, P2, P3 are all closed, and the output pressure is maintained.

FIG. 1 is a block diagram showing details of the control unit 65. In the figure, a controller 65 calculates a AC pressure change rate (output pressure change rate) ΔP _AC based on the output pressure of the three-position solenoid valve 61 detected by the output pressure sensor 64, and a differential circuit 65a. calculated by the differentiating circuit 65a the AC pressure change rate [Delta] P _AC, and the coil current determination unit 65b determines coil current based on AC pressure feedback signal value P _AC, and the fluid pressure command value P _ACO from output pressure sensor 64, A drive circuit 65c that drives the three-position solenoid valve 61 by changing the exciting current to a predetermined value based on the determination signal determined by the coil current determination unit 65b, and provides a fluid pressure command value P _ACO and an output The three-position solenoid valve 61 is controlled so as to compare the pressure feedback signal value P _AC with the pressure feedback signal value P _AC and to switch the three-position solenoid valve 61 to a position where the difference is matched. The drive circuit 65c includes a PWM control unit, a transistor, and the like.

[0023] In the above structure, the fluid pressure command value P _ACO from the brake control unit 50 is input to the coil current determining unit 65b. Further, the AC pressure feedback signal from the output pressure sensor 64 is input to the coil current determination unit 65b and also to the differentiating circuit 65a. Differentiator 6
5a differentiates the AC pressure feedback signal value P _AC from the output pressure sensor 64 and outputs the AC pressure change rate ΔP _AC to the coil current determination unit 65b. Coil current determination unit 65
b determines the coil current based on the AC pressure change rate ΔP _AC , the AC pressure feedback signal value P _AC , and the fluid pressure command value P _ACO , and outputs a determination signal to the drive circuit 65c. The drive circuit 65c drives the three-position solenoid valve 61 by changing the exciting current to a predetermined value based on the determination signal from the coil current determination unit 65b.

2 and 3 are flowcharts showing the control operation of the fluid pressure control device 10, FIG. 4 is a timing chart of the control operation, and FIG. 5 is a timing chart of the guarantee operation. Table 1 shows an example of the contents of the symbols in these figures and the corresponding constant values.

[0025]

[Table 1]

The constant values shown in Table 1 are stored in the coil current determination unit 65b of the fluid pressure control device 10.
Further, in Table 1, the hysteresis ΔH of the AC pressure tolerance ΔT is provided in order to prevent the hunting of the solenoid valve command, but for convenience of explanation, FIGS. 2 and 3 show the hysteresis ΔH.
H is not considered.

Referring to FIGS. 2 and 3, when the fluid pressure command value P _ACO is output from the brake control unit 50, the coil current determination unit 65b of the fluid pressure control device 10 sets the fluid pressure command value P _ACO Is read and the fluid pressure command value P _ACO is calculated and determined (the calculated value is the “AC pressure calculation value P _ACO ” in Table 1), and the AC pressure is calculated based on the output signal of the output pressure sensor 64. The feedback signal value _PAC is read (steps S1, S2). Then, the coil current determination unit 65b determines whether the calculated AC pressure value P _ACO is equal to or less than 0 (Step S3). Here, the fluid pressure command value P _ACO from the brake control unit 50 is P _ACO > 0.
When it is judged, 3 output pressure position solenoid valve 61, AC pressure tolerance ΔT first dead zone (slow feed control zone) or less or not than [Delta] P _L which is set on the lower side of, i.e. P _AC < P _ACO
It is determined whether or not − (ΔT + ΔP _L ) (step S
4).

If the output pressure of the three-position solenoid valve 61 is smaller than the first dead zone ΔP _L , the coil current determination unit 65b determines the coil current at which the three-position solenoid valve 61 should be set to the supply position. Then, the determination signal is output to the drive circuit 65c. Then, the drive circuit 65c sets the coil current determination unit 65
The exciting current is changed to a predetermined value based on the determination signal from b, the 3-position solenoid valve 61 is set to the supply (brake) position (step S10), and the process returns to step S1. Supply position of the 3-position solenoid valve 61 3 output pressure position solenoid valve 61, a first dead zone [Delta] P _L from the lower side of the first dead band [Delta] P _L
It is held until it enters.

The coil current judging section 65b determines in step S4
The output pressure of the three-position solenoid valve 61 is equal to the first dead zone Δ
If determined to be larger than P _L, 3 output pressure position solenoid valve 61, AC pressure second dead zone that is set on the upper side of the tolerance [Delta] T (slow exhaust control zone) [Delta] P or not greater than _U, i.e. P _It is determined whether or not _AC > P _ACO + (ΔT + ΔP _U ) (step S5). If it is determined that the pressure is smaller than the second dead zone ΔP _U , the output pressure of the three-position solenoid valve 61 is further reduced to the first dead zone ΔP _L. , That is, P _ACO − (ΔT + ΔP
_L ) It is determined whether or not ≦ P _AC ≦ P _ACO −ΔT (step S6). Here, when the output pressure of the three-position solenoid valve 61 is in the first dead zone ΔP _L , the coil current determination unit 65b sets the AC pressure change rate to the reference change rate (reference AC) based on the calculation result of the differentiating circuit 65a. Pressure change rate), that is, whether ΔP _AC > + ΔP _ACB or not (step S1).
2). In this first deadband [Delta] P _L reaches point 4
As shown by the solid line in (c), when the AC pressure change rate ΔP _AC is larger than the “positive” reference AC pressure change rate + ΔP _ACB , the coil current determination unit 65b sets the three-position solenoid valve 61 to the overlapping position. A coil current to be determined is determined, and a determination signal is output to the drive circuit 65c. Then, the drive circuit 65c changes the excitation current to a predetermined value based on the determination signal from the coil current determination unit 65b, and sets the three-position solenoid valve 61 to the overlapping position as shown by the solid line in FIG. Step S1
3), the process returns to step S1.

On the other hand, in the first deadband [Delta] P _L reaches point, as shown by the broken line in FIG. 4 (c), AC pressure change rate Δ
If P _AC is smaller than the “positive” side reference AC pressure change rate + ΔP _ACB , the coil current determination unit 65 b
Is supplied slowly (slow brake), and the process returns to step S1 while providing a guarantee operation described later (steps S14 to S18). The slow supply state of the three-position solenoid valve 61 is shown in FIG.
As shown by the broken line in (b) (c), 3 output pressure position solenoid valve 61 is held until it reaches the point that can absorb hysteresis ΔH of the first deadband [Delta] P _L side of the AC pressure tolerance [Delta] T, 3 position solenoid valve 61, the output pressure is set to overlap the position at the time that could absorb the hysteresis ΔH of AC pressure tolerance ΔT of the first deadband [Delta] P _L side. Note that the AC pressure change rate [Delta] P _AC of large and small, and the rate of change of fluid pressure command value P _ACO, before and after the change of the fluid pressure command value P _ACO 3 position solenoid valve 61
This is caused by a difference between the output pressures.

Then, for example, the brake controller of the driver's cab is operated so as to reduce the braking force, and step S3 is performed.
When it is determined that P _ACO ≦ 0, the three-position solenoid valve 61
Is determined as the coil current to be set as the exhaust position, and a determination signal is output to the drive circuit 65c. Then, the drive circuit 65c
The excitation current is changed to a predetermined value based on the determination signal from the coil current determination unit 65b, the 3-position solenoid valve 61 is set to the exhaust (Urme) position (step S9), and the process returns to step S1.

[0032] In the Loose operation time, the coil current determination unit 65b is passed through the steps S1 to S4, 3 whether the output pressure of the position solenoid valve 61 is above the second dead band [Delta] P _U, i.e. P _AC > P _ACO + (ΔT + ΔP _U )
It is determined whether or not this is the case (step S5). Then, until the output pressure of the three-position solenoid valve 61 enters the second dead band [Delta] P _U, while maintaining the exhaust (Loose) Condition 3 position solenoid valve 61 (step S11), and the process returns to step S1.

The coil current judging section 65b determines in step S6
The output pressure of the three-position solenoid valve 61 is equal to the first dead zone Δ
When determining that not in the P _L, the output pressure of the 3-position solenoid valve 61 is, whether the second dead band [Delta] P _U, i.e. P _ACO
It is determined whether or not + ΔT ≦ P _AC ≦ P _ACO + (ΔT + ΔP _U ) (step S7). Here, the output pressure of the three-position solenoid valve 61, when it is determined to be in a second dead band [Delta] P _U, based on the calculation result of the differentiating circuit 65a, the absolute value of the rate of change of the output pressure of the three-position solenoid valve 61 is, It is determined whether or not the absolute value of the reference change rate on the “negative” side is smaller, that is, ΔP _AC <−ΔP _ACB (step S19). This second dead zone Δ
At the point of time when P _{U is} reached, as shown by the solid line in FIG. 4D, the AC pressure change rate ΔP _AC is the reference change rate −Δ on the “negative” side.
If it is smaller than P _ACB , the coil current determination unit 65b
It is determined that P _AC <−ΔP _ACB , the coil current at which the three-position solenoid valve 61 is to be in the overlapping position is determined, and a determination signal is output to the drive circuit 65c. Then, the drive circuit 65c changes the excitation current to a predetermined value based on the determination signal from the coil current determination unit 65b, and changes the excitation current to 3 as shown by the solid line in FIG.
The position solenoid valve 61 is set to the overlapping position (step S20),
It returns to the process of step S1.

On the other hand, at the point of time when the second dead zone ΔP _{U is} reached, as shown by the broken line in FIG.
If the absolute value of P _AC is larger than the reference change rate on the “negative” side, the coil current determination unit 65b determines that ΔP _AC ≧ −ΔP _ACB, and as shown in FIG. Is returned to the process of step S1 while performing the assurance operation to be described later (step S21 to S25).
The slow exhaust state of the three-position solenoid valve 61 is shown in FIG.
As shown by the broken line in (b) (c), 3 output pressure position solenoid valve 61 is held until reduced to the time to absorb the hysteresis ΔH of the second dead band [Delta] P _U side of the AC pressure tolerance [Delta] T, 3 position solenoid valve 61, the output pressure is set to overlap the position at the time that could absorb the hysteresis ΔH of AC pressure tolerance ΔT of the second dead band [Delta] P _U side.

In step S12, when the coil current determination unit 65b determines that ΔP _AC ≦ + ΔP _ACB ,
The guarantee operation on the slow supply (slow brake) side is performed. That is, the coil current determination unit 65b supplies the three-position solenoid valve 61 slowly (slow brake) as shown by the broken line in FIG.
The state is continued for the monitoring time _TGH (steps S14 and S1).
5) When the monitoring time T _GH elapses, the coil current determination unit 6
5b, the three-position solenoid valve 61 is forcibly supplied (brake) for the forced supply time T _GS (steps S16 and S16).
17). Then, when the forced supply time T _GS elapses, the coil current determination unit 65b puts the three-position solenoid valve 61 into a slow supply (slow brake) state (step S18).

On the other hand, in step S19, when the coil current determination unit 65b determines that ΔP _AC ≧ −ΔP _ACB ,
The guaranteed operation on the gentle exhaust (gentle) side is performed. That is, the coil current determination unit 65b, as shown in FIG. 5 as indicated by the solid line in (a), 3 a slow exhaust (slow Loose) state position solenoid valve 61 continues for monitoring time T _GH (step S21, S2
2) When the monitoring time T _GH elapses, the coil current determination unit 6
5b, only a forced exhaust (Loose) state 3 position solenoid valve 61 to force the exhaust time T _GE (step S23, S2
4). Then, when the forced supply time T _GE elapses, the coil current determination unit 65b puts the three-position solenoid valve 61 into a slow exhaust (slow exhaust) state (step S25). As shown in FIGS. 5A and 5B, after the three-position solenoid valve 61 is slowly supplied or slowly exhausted, the output pressure (AC pressure) of the three-position solenoid valve 61 is changed to the AC pressure as shown in FIGS. This is repeated until the tolerance ΔT is converged.

Incidentally, an example of a current value for controlling the three-position solenoid valve 61 is shown in Table 2 in percentage.

[Table 2]

[0038] According to the fluid pressure control device 10 of the above configuration, 3 output pressure position solenoid valve 61 is first present in the dead zone [Delta] P _L which is set on the lower side of the AC pressure tolerance [Delta] T, and A
When the C pressure change rate ΔP _AC is smaller than the reference AC pressure change rate ΔP _ACB , the three-position solenoid valve 61 is set to a gentle supply position between the supply position and the overlap position, and a gentle supply of fluid is performed. Can be done. The output pressure is A
Present in the second dead band [Delta] P _U of the upper C pressure tolerance [Delta] T,
And the AC pressure change rate ΔP _AC is the reference AC pressure change rate ΔP
_When it is larger than the _ACB , the three-position solenoid valve 61 can be set to the gentle exhaust position between the exhaust position and the overlapping position, and the fluid can be exhausted slowly. Therefore, the output pressure of the three-position solenoid valve 61 can be quickly converged within the pressure tolerance of the fluid pressure command value by suppressing or preventing the overshoot and the undershoot.
Therefore, the response characteristics of the three-position solenoid valve 61 can be improved. Further, since the three-position solenoid valve 61 can be prevented from being frequently switched, the durability and reliability of the three-position solenoid valve 61 can be improved.

The output pressure of the three-position solenoid valve 61 exists in the dead zones ΔP _L , ΔP _U and the AC pressure change rate ΔP
_{If AC} is greater than the reference AC pressure change rate ΔP _ACB as an absolute value, an overlap command is output.
When the output pressure of (1) suddenly approaches the command pressure, the three-position solenoid valve 61 can be set from the supply position to the overlap position without being set to the gentle supply position or the gentle exhaust position. For this reason, overshoot can be suppressed or prevented more effectively.

Further, when the slow supply command value or the slow exhaust command value continues for a prescribed time, a fluid pressure command value for setting the three-position solenoid valve 61 to the supply position or the exhaust position is output. Even in the slow exhaust state, it is possible to guarantee that the output pressure does not converge within the pressure tolerance of the fluid pressure command value due to slight air leakage or malfunction of the solenoid valve.

The present invention is not limited to the above embodiment. For example, in the above embodiment, in the assurance operation, the three-position solenoid valve 61 is forcibly supplied from the slow supply state and the slow exhaust state. The time to switch to the exhaust state is T
_{Although the case where GS} and _TGE are set is described, the three-position solenoid valve 61 is forcibly supplied to the supply position or the exhaust position on condition that the slow supply command value or the slow exhaust command value has continued for the specified time _TGH. May be continuously output.

[0042]

As described above, according to the fluid pressure control device of the first aspect, when the output pressure is in the gentle position control band and the fluid pressure command value is larger than the output pressure, 3 The position solenoid valve is set to a gradual supply position between the supply position and the overlap position so that gradual supply can be performed, the output pressure exists in the gradual position control zone, and the fluid pressure command value is output. When the pressure is smaller than the pressure, the three-position solenoid valve is set to a gentle exhaust position between the exhaust position and the overlap position, so that gentle exhaust can be performed, so that overshoot and undershoot are suppressed or Thus, the output pressure of the three-position solenoid valve can quickly converge to the target pressure. Therefore, the response characteristics of the three-position solenoid valve can be improved. Further, since the three-position solenoid valve can be prevented from being frequently switched, the durability and reliability of the three-position solenoid valve can be improved.

According to the fluid pressure control device of the second aspect,
When the output pressure of the three-position solenoid valve suddenly approaches the command pressure, the three-position solenoid valve can be set to the overlapping position without setting to the gentle supply position or the gentle exhaust position. Shooting can be suppressed or prevented more effectively.

According to the fluid pressure control device of the third aspect,
If the slow supply command value or slow exhaust command value continues for the specified time,
Since the fluid pressure command value for setting the three-position solenoid valve to the supply position or the exhaust position is output, even if the three-position solenoid valve is slowly supplied and slowly exhausted, the output pressure may be reduced due to slight air leakage or malfunction of the solenoid valve. This can be guaranteed if does not converge within the pressure tolerance of the fluid pressure command value.

[Brief description of the drawings]

FIG. 1 is a block diagram of a fluid pressure control device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of the fluid pressure control device.

FIG. 3 is a flowchart showing the operation of the fluid pressure control device.

FIG. 4 is a timing chart of a control operation.

FIG. 5 is a timing chart of a guarantee operation.

FIG. 6 is a block diagram conceptually showing a configuration of a brake control device for a railway vehicle to which the fluid pressure control device of the present invention is applied.

FIG. 7 is a block diagram of a brake pressure output device.

[Explanation of symbols]

 Reference Signs List 10 fluid pressure control device 61 3-position solenoid valve 64 output pressure sensor 65 control unit 65a differentiation circuit 65b coil current determination unit 65c drive circuit

Claims (3)

[Claims] 1. A three-position solenoid valve for generating an output pressure by selectively switching to a supply position, an exhaust position, and an overlapping position in response to a fluid pressure command, and a feedback signal of a fluid pressure command value and an output pressure. And a control unit that controls switching of the three-position solenoid valve to a position where the difference is matched by comparing the three-position solenoid valve with a supply command value that sets the three-position solenoid valve as a supply position. A slow supply command value that sets the three-position solenoid valve to a slow supply position;
A storage means for storing a slow exhaust command value which is a value between an exhaust command value for setting the position solenoid valve to the exhaust position and an overlap command value, and wherein the output pressure is: It is determined that the fluid pressure command value is present in the gentle position control zone set outside the pressure tolerance of the output pressure, and the command pressure corresponding to the fluid pressure command value is larger than the output pressure. Outputting the slow supply command value stored in the storage means, determining that the output pressure is present in the slow position control zone, and providing the storage pressure to the storage means on condition that the command pressure is smaller than the output pressure. Command control means for outputting a stored gentle exhaust command value. The command control means outputs a slow supply command or a slow exhaust command when it is determined that the output pressure is in the slow position control zone and the rate of change is smaller than the reference rate of change as an absolute value. And output means for outputting an overlap command when it is determined that the output pressure is in the gentle position control band and the rate of change is greater than the reference rate of change as an absolute value. The slow supply command value stored in the storage means is output on the condition that the output pressure is smaller than the output pressure, and the slow exhaust gas stored in the storage means is provided on the condition that the output pressure is higher than the command pressure. The fluid pressure control device according to claim 1, wherein the fluid pressure control device outputs a command value. 3. The command control means outputs the supply command value or the exhaust command value on condition that the slow supply command value or the slow exhaust command value stored in the storage means has continued for a specified time. 3. The method according to claim 1, wherein
The fluid pressure control device according to any one of the preceding claims. [0001]