JPH0640324A - Hydraulic brake device for rolling stock and method for controlling hydraulic brake device for rolling stock - Google Patents

Abstract

PURPOSE:To short braking distance by hasting brake starting time and provide safe braking force corresponding to the weight of vehicle body while pumps and control valve and broken in a hydraulic brake device for rolling stock. CONSTITUTION:A hydraulic brake device for rolling stock is provided with a cylinder 7 for driving the piston rod 7a with a brake shoe, pressure gauge 13 to measure the pressure of pressure fluid, a flow control valve 6 to control the supply and discharge of the pressure fluid controlled by a controller 14, and second flow control valves 19 are juxtaposed with the flow control valve 6 for supplying pressure fluid to the cylinder 7 directly after the start of applying braking and cutting off the supply of pressure fluid when pressure reaches a specified value. A check valve is provided in a return pipe to hold cylinder pressure unchanged while braking is not operated to shorten brake delay time, and in addition, vehicle speed is determined from acceleration and the electric current of a driving motor, and braking force is generated according to the result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a railway vehicle fluid brake system and a railway vehicle brake control method capable of solving the drawbacks of conventional systems.

[0002]

2. Description of the Related Art One of conventional hydraulic brake devices for railway vehicles
An example is shown in FIG. In this conventional device, when the brake is applied to decelerate during high-speed traveling, the flow rate control valve 6 controlled by the signal from the controller 14 to which the signal r from the driver is input is moved from position (a) to position (a). C), the high pressure oil discharged from the pump 2 into the pipe line 23 is supplied into the cylinder 7 having the built-in spring through the check valve 4 and the pipe lines 22 and 22 and is stored in the cylinder 7. The piston rod 7a of the piston is stroked, and the brake shoe 8 connected to the tip of the piston rod 7a is pressed against the rotating friction plate 9 connected to the wheel 10 to generate a braking force to reduce the speed of the railway vehicle. If the wheels 10 on the rails 11 are about to slip, the pressure in the cylinder 7 is lowered and the braking force is weakened. This slows down the railway vehicle without slipping. The braking force can be adjusted by the magnitude of the pressure in the cylinder 7.

For this pressure adjustment, the pressure oil discharged from the pump 2 is supplied to the cylinder 7 (the control valve 6 is set to the position (c) as described above), or the oil in the cylinder 7 is supplied to the tank 1. The flow is controlled by the flow control valve 6 that controls the oil supply / discharge to / from the cylinder 7 such as discharging (setting the control valve 6 to the position (a)).

Further, an accumulator 5 to which pressure oil is supplied from the pump 2 via the check valve 4 is provided. The accumulator 5 stores the pressure oil to make up for a temporary shortage of the pump discharge amount, and at the time of pump failure. In case of, it has the role of storing the necessary pressure oil for minimum braking.

That is, when the brake is not operated, the control valve 6 is in the position (a), and the accumulator 5 is supplied with pressure oil from the pump 2 through the check valve 4. Then, more oil than necessary returns to the tank 1 through the relief valve 3, and the accumulator 5 stores pressurized oil of a predetermined pressure. Therefore, when the brake in which the control valve 6 takes the position (c) is applied, the pressure oil from the accumulator 5 is supplied to the cylinder 7 in addition to the pressure oil from the pump 2, and the minimum brake is applied even when the pump fails. You can get it.

On the other hand, when the railway vehicle is braked and stopped, it is desirable that the wheel 10 does not idle and the vehicle stops for a short distance. Therefore, the idling of the wheel 10 is detected by a rotation sensor for detecting the rotational speed of the friction plate 9. The signal N _S is detected by 12, and the signal N _S is input to the controller 14. A speed signal of a plurality of wheels (not shown) is inputted to the controller 14, and the speed of the wheel having the slowest speed with less slip is set as the vehicle speed, and the idling of the wheel 10 is detected by this and the signal N _S. However, when the wheels 10 run idle, a command is issued to the control valve 6 to weaken the braking force.

Further, the pressure of the pressure oil supplied to the cylinder 7 is detected by the pressure gauge 13, and the signal P _B thereof is inputted to the controller 14, and the controller 14 makes the pressure of the pressure oil supplied to the cylinder 7 appropriate. Feedback control is performed to issue a command to the control valve 6 so that the value becomes a value.

In FIG. 14, u is the controller 1
4 shows a signal from the control valve 6 to the control valve 6, and 3 controls the upstream side of the check valve 4 in the discharge side pipe line 23 of the pump 2 in order to make the pressure of the accumulator 3 a prescribed set pressure. A relief valve provided in a pipe line 27 connecting the valve 6 and the return pipe line 26 between the oil tank 1, 20 is a pipe line connecting the portion of the pipe line 23 near the inlet of the accumulator 5 and the control valve 6, 22 Is a conduit connecting the control valve 6 and the cylinder 7.

Further, in the hydraulic brake device for a railway vehicle such as the hydraulic brake device shown in FIG. 14, a command r is input to the controller 14 so that an appropriate brake pressure is obtained during braking. When a railway vehicle is decelerated by braking from high speed operation, it is generally necessary to obtain a constant deceleration, but at this time, the required braking force also changes depending on the number of passengers, that is, the weight of the vehicle body. That is, when the weight is large, the braking force is large, and when the weight is light, the braking force needs to be small. Therefore, it is necessary to measure the vehicle body weight.

As shown in FIG. 13, the structure of a conventional vehicle is a trolley 62 having wheels 60 running on the rail 11.
The vehicle body 61 and the vehicle body 61 are connected by an air spring 63 having a suspension function. By measuring the pressure of the air spring 63, the vehicle body weight W
I was able to ask for _one . That is,

[0011]

[Equation 1]

The vehicle body weight W ₁ is obtained by the following.

FIG. 15 shows another example of the conventional hydraulic brake device for railway vehicles. In this hydraulic brake device, the following is added to the conventional brake device shown in FIG.

That is, from the pipe line 23 on the discharge side of the pump 2,
A pipe line 24 that has the pressure reducing valve 16 and the check valve 17 and reaches the second accumulator 18 branches, and one end of the pipe line 25 is connected between the check valve 17 and the second accumulator 18 of the pipe line 24. There is. A switching valve 30 is provided in the pipe line 22 at a position upstream of the pressure gauge 13, and the other end of the passage 25 is connected to the switching valve 30.
The portion of the second accumulator 18, the pipe line 25 and the switching valve 30 downstream of the check valve 17 constitutes a hydraulic circuit for a backup or parking brake.

In this conventional hydraulic brake device, when the brake is not operated, the switching valve 30 is in the position (x) and is set by the pressure reducing valve 16 in addition to the accumulator 5 and is lower than the pressure in the accumulator 5 by a predetermined value. The pressure oil having the pressure of is stored in the second accumulator 18.

The switching valve 30 selects a normal braking action or a preliminary braking action and a parking brake action. During normal braking, the switching valve is set to the position (x) and the switching valve 30 is removed from the control valve 6. Pressure oil is supplied to the cylinder 7. On the other hand, the switching valve 30 is set to the position (y) at the time of preliminary braking such as when the pump 2 fails or the control valve 6 becomes defective, or during parking braking when the vehicle stops.
Pressure oil is supplied to the cylinder 7 from the second accumulator 18. At this time, in order to prevent the braking force from being too high and the wheel 10 from slipping or damaging the shoe 8, the pressure of the pressure oil in the second accumulator 18 is set to the predetermined value by the pressure reducing valve 16 as described above. It is set to a value.

Other than the above, in this hydraulic brake device,
An operation similar to that of the hydraulic brake device shown in FIG. 14 is performed.

[0018]

[Problems to be Solved by the Invention]

(A) In the conventional hydraulic brake device for a railway vehicle shown in FIGS. 14 and 15, in order to stop the railway vehicle running at high speed at the shortest distance, the driver gives a brake command r.
It is necessary to immediately press the brake shoe 8 at the tip of the piston rod 7a against the mating friction plate 9 with minimum force, and then control the pressing force so that the slip ratio of the wheel and rail does not deviate from the optimum value. Is. For this purpose, it is essential to control the pressure in the cylinder with high response. The control of the pressure in the cylinder is, as described above, performed by the feedback control in which the pressure is detected by the pressure gauge 13 and the controller 14 issues an opening / closing command to the flow control valve 6 so that the pressure becomes an appropriate value. However, in a railway vehicle, generally, the distance between the control valve 6 and the cylinder 7 is long, and therefore even if a command is issued to the control valve 6, there is a delay in the pressure following, and if the feedback gain is increased, oscillation will occur. Will occur. Therefore, there is a limit to the responsiveness of pressure control. (B) In the conventional hydraulic brake device for a railway vehicle shown in FIGS. 14 and 15, at the beginning of braking, the piston rod 7a needs to stroke until the brake shoe 8 comes into contact with the friction plate 9. Since the pressure in the cylinder is almost equal to the atmospheric pressure, even if the flow control valve 6 is opened and the hydraulic pressure is applied to the cylinder 7, the piston rod is kept until the hydraulic pressure in the cylinder rises to a pressure that overcomes the spring force in the cylinder. 7a remains stationary. Therefore, the action of the brake is delayed at the beginning of braking, and in addition, when the brake is not activated, the pressure in the cylinder is low, which is almost equal to the atmospheric pressure. There is a problem that bubbles are generated and the rise of hydraulic pressure is delayed when the brake is applied. (C) In the conventional railway vehicle hydraulic brake device shown in FIGS. 14 and 15, the accumulator is provided so that the brake can be secured even when the pump cannot be discharged. Moreover, leakage of the control valve and the pressure reducing valve cannot be avoided. For this reason, a large-sized accumulator is required, which increases the weight of the accumulator, which is not desirable for increasing the speed of a railway vehicle that is particularly required to be lightweight. (D) In the railway vehicle hydraulic brake device shown in FIGS. 14 and 15, the command u from the controller 14 to the control valve 6 is a deviation (r−P _B ) between the brake pressure command r and the cylinder pressure P _B. Was multiplied by a constant control gain K _B. That is _{u = K B (r-P} B). As the demand for high-speed railway vehicles has increased in recent years, there is a growing need to improve brake responsiveness and shorten the brake distance for safety reasons. Considering the case where pressure oil is put into the cylinder 7 from the flow control valve 6 to operate the brake, the piston rod 7a first makes a stroke until the shoe 8 is pressed onto the friction plate 9, and the shoe 8 moves. After being pressed against 9, the pressure inside the cylinder 7 rises,
The brake comes to work. At this time, the amount of liquid Q ₁ that the piston rod 7a strokes and the amount of liquid Q ₂ required for pressurization after being pressed are as follows.

Q ₁ = A × S Q ₂ = K / V × P ₁ A: Cylinder cross-sectional area S: Stroke K: Hydraulic fluid bulk modulus V: Oil volume between control valve and cylinder Q ₁ and When Q ₂ is quantitatively compared, the relationship is Q ₁ >> Q ₂ .

In the conventional device, the control gain K _B of the control system is fixed as shown in FIG. 10 (b), and the rising characteristic of the brake pressure is stroked as shown in FIG. 11 (b). The time T ₂ required for occupies most of the time. If the control gain K _B is increased in order to shorten the time required for this stroke, there is a problem in that the pressure increase gradient at the time of pressing becomes too large and vibration occurs. (E) In recent years, there has been a great demand for improving the riding comfort of railway vehicles.
For this reason, as a suspension system, instead of the conventional passive air spring shown in FIG. 13, a system for positively controlling the pressure of the air chamber to reduce the movement of the vehicle body is being adopted. In this method, since the air pressure constantly changes, it is difficult to accurately obtain the weight of the vehicle body.

The present invention is intended to provide a railway vehicle fluid brake device and a railway vehicle brake control method capable of confronting the above problems in the conventional device.

[0022]

According to the present invention, a brake shoe connected to a piston rod inserted into a cylinder to which pressurized fluid is supplied and discharged, and the pressure of the pressurized fluid supplied to the cylinder are measured. In a hydraulic brake device for a railway vehicle, which includes a pressure gauge, a controller to which a signal of the pressure gauge is input, and a control valve to which a command of the controller is input and which controls supply and discharge of pressurized fluid to and from the cylinder, Measures have been taken. (1) A second control valve which is provided in parallel with the control valve and which is opened immediately after the start of braking to supply the pressurized fluid to the cylinder and is closed when the pressure in the cylinder reaches a predetermined value. It is characterized by that. (2) A check valve for blocking the flow of fluid in the direction from the tank to the control valve is provided in the return pipe from the control valve to the tank. (3) A means for changing the volume volume of the fluid circuit between the control valve and the cylinder is provided. (4) Any one of a pressurized fluid accumulator capable of supplying a pressurized fluid to the cylinder via a control valve, a second accumulator capable of supplying a pressurized fluid to the cylinder, and the accumulator and the second accumulator. A switching valve that selectively connects the cylinder to the cylinder, and a cylinder that has both ends connected to a conduit from the accumulator to the cylinder and a conduit from the second accumulator to the cylinder and has a built-in piston. It is characterized by that. (5) The control gain of the controller is variable so as to decrease when the cylinder pressure increases. (6) Further, in the railway vehicle brake control method of the present invention, the vehicle body weight is obtained from the acceleration calculated by the accelerometer or the speedometer and the current flowing through the drive motor of the vehicle, and the braking force corresponding to the vehicle weight is obtained. It is characterized by generating.

[0023]

In the present invention (1), the control valve is feedback-controlled by the pressure of the pressurized fluid supplied to the cylinder measured by the pressure gauge to control the pressurized fluid supplied to the cylinder. , The pressure in the cylinder and thus the braking force is controlled. Further, in the present invention (1), by opening the second control valve provided in parallel with the control valve immediately after the start of braking, the pressurized fluid is passed through the second control valve in addition to the control valve, and the pressurized fluid is transferred to the cylinder. When the piston rod is rapidly stroked, the braking force acts in a short time. When the pressure in the cylinder reaches a predetermined value, the second control valve is closed, and thereafter, as described above, the braking force is controlled via the control valve so that the slip rate of the wheel becomes optimum. In this way, the present invention (1) applies a braking force in a short time at the start of braking to reduce the traveling distance to the start of braking without impairing the stability of the pressure feedback system and reduce the braking distance. Can be reduced.

In the present invention (2), a check valve for blocking the flow of fluid from the tank to the control valve is provided in the return pipe from the control valve to the tank, and even when the brake is not operated, The pressure in the cylinder is higher than the atmospheric pressure, which is almost equal to the force of the spring in the cylinder. As a result, the fluid pressure in the cylinder rises quickly at the beginning of braking, and the brake operates without time delay.
When the brake is not operated, the fluid pressure in the cylinder is increased so that no bubbles are generated in the fluid, and the fluid pressure is quickly increased when the brake is applied.

In the present invention (3), since the means for changing the volume of the fluid circuit is provided between the control valve and the cylinder, even if there is a leak in the control valve or the like, the means for changing the volume of the fluid circuit is provided in the cylinder. The fluid pressure can be set to an appropriate value. Further, the accumulator used when the pump cannot be discharged during normal braking is abolished and the weight is reduced.

In the present invention (4), when the pressure of the pressurized fluid in the pipeline from the accumulator to the cylinder decreases due to the damage of the pump pipeline, the control valve, etc., the piston in the volume cylinder has the above pressure. Move to the side of the pipe that has deteriorated. As a result, the volume volume of the pressurized fluid in the conduit from the second actuator to the cylinder is increased, and the pressure is reduced accordingly. In this way, the pressure of the pressurized fluid supplied from the second actuator to the cylinder is reduced, and a safe brake can be applied to the vehicle without control by the control valve, pressure reducing valve, or the like.

In the present invention (5), the control gain of the controller is made variable from the conventional fixed value, the control gain is large when the cylinder pressure is small and the piston rod is in the stroke, and the control gain is set when the shoe is pressed to increase the cylinder pressure. Make it smaller. As a result, the time required for the stroke of the piston rod is shortened, and when the shoe is pressed, the pressure gradient at the time of pressing the shoe is reduced and vibration is suppressed.

The acceleration of a railway vehicle during acceleration is proportional to the output of the drive motor of the vehicle and inversely proportional to the vehicle body weight.
Also, the output of the drive motor is determined by the current flowing through the motor. In the present invention (6), the vehicle body weight is simply and accurately obtained by the acceleration calculated by the accelerometer or the speedometer and the current flowing through the drive motor of the vehicle, and the braking force corresponding to the vehicle body weight is generated. . by this,
It is possible to obtain the optimum braking force according to the vehicle body weight.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. The present embodiment relates to a hydraulic brake device for a railway vehicle of the same type as that shown in FIG. 15, and the corresponding parts in FIG. 1 are given the same reference numerals as in FIG. Differences will be described.

Bypass line 2 having a control valve 19 having a second flow rate, which is branched from a line 20 connected to the discharge side line 23 of the pump 2 near the inlet of the accumulator 5 and reaching the control valve 6.
1 is provided, the bypass conduit 21 bypasses the control valve 6 and joins the conduit 22 that connects the control valve 6 and the cylinder 7, and the second control valve 19 is parallel to the control valve 6. It is arranged. As in the case shown in FIG. 15, the controller 14 receives the signal N _{S from} the rotation sensor 12 and the signal P _{B from the} pressure gauge 13, and the control valve 6 is controlled by the signal u ₁ . But the controller 14
The second control valve 19 is controlled by the signal u ₂ . Reference numeral 15 is a pressure gauge provided on the downstream side of the check valve 4 in the pipe line 23. Also, check valve 1
The portion of the accumulator 18, the pipe line 25, and the switching valve 30 on the downstream side of 7 constitutes a hydraulic circuit of a backup or parking brake.

In this embodiment, when the brake is not operated,
The pressure oil discharged from the pump 2 passes through the check valve 4 and fills the accumulator 5, and the pressure reducing valve 16 and the check valve 1
7 through which the second accumulator 18 is filled. Then, more oil than necessary returns to the tank 1 through the relief valve 3, and the accumulators 5 and 18 store pressure oil of a predetermined pressure. When the brake is not operated, the control valve 6 is in the position (a), the second control valve 19 is in the position (a), the inside of the cylinder 7 is in communication with the tank 1, and the brake shoe 8 and the friction plate are in communication. 9 are distant.

Next, when the driver sends a command r to the controller 14 in order to stop the railway vehicle, the controller 14
Outputs the signals u ₁ and u ₂ that bring the control valve 6 to the position (c) and the second control valve 19 arranged in parallel with the control valve 6 to the position (b), and both control valves 6 and 19 are turned on. Supply into the pressure oil cylinder 7 via

FIG. 2 shows changes in the piston stroke, the openings of the flow rate control valves 6 and 19 and the pressure in the cylinder at this time. The piston makes a stroke from time t _{0 when the} command r is sent to time t ₁ , and the cylinder pressure does not rise during that time. When the shoe 8 hits the friction plate 9, the piston stops, and then the cylinder pressure starts to increase and the braking force acts (brake rising).

When the pressure reaches P _Bu (time t ₂ ), the second control valve 19 is closed in the position (a) by the signal u ₂ of the controller 14 to which the signal of the pressure gauge 13 is input. The value of P _Bu is selected in advance so that the slip of the wheel 10 does not rise abnormally even in rainy weather.
After that (after time t ₂ ), the slip ratio between the wheel 10 and the rail 11 becomes optimum (the braking force is maximum) by the signal of the rotation sensor 12 and the signal of the pressure measured by the pressure gauge 13. As described above, the control valve 6 is controlled by the controller 14, and thereby the pressure P _B in the cylinder 7 is feedback-controlled.

The switching valve 30 selects a normal braking action or a preliminary braking action and a parking brake action similarly to the hydraulic braking device shown in FIG. 15. During normal braking, the switching valves 30 are controlled by the control valves 6 and 19. The position (x) is illustrated so that the amount of oil that has been discharged is connected to the cylinder 7. On the other hand, the accumulator 18 is provided as a hydraulic pressure source for a preliminary brake when the control valves 6 and 19 are defective or a parking brake when the vehicle is stopped. In this case, the switching valve 30 is provided.
Is switched to position (y) so that the line 25 connected to the accumulator 18 is connected to the cylinder 7.
At this time, if the braking force is too high, the wheels 10 may slip or the shoes 8 or the like may be damaged. Therefore, the pressure in the accumulator 18 is set by the pressure reducing valve 16 so that the braking force becomes appropriate.

Further, the relief valve 3 is a vent type, and when the prescribed pressure oil is stored in the accumulator 5, the set pressure of the relief valve 3 is minimized to reduce the load of the pump 2 and reduce the heat. Generation and power consumption are minimized.

The control valve 6 and the second control valve 19 described above are used.
The difference between the control methods is that the control valve 6 performs feedback control so that the brake pressure follows the command pressure, but the second control valve 19 is fully open only during a certain period.
This is because it is off control.

Corresponding to FIG. 2 showing the state at the time of starting the brake of this embodiment, FIG. 3 shows the state at the time of starting the brake of the conventional hydraulic brake device for a railway vehicle shown in FIG. In FIG. 3, t ₃ indicates the brake rising time.

As is apparent from FIGS. 2 and 3, t ₁ <
Since it is t ₃ , in the present embodiment, the traveling distance until the start of braking is shortened and the braking distance can be shortened. Further, in the present embodiment, the control valve 6 is controlled by the controller 14 based on the pressure of the pressure oil supplied to the cylinder 7 measured by the pressure gauge 13 in addition to the wheel rotation speed detected by the rotation speed sensor 12, Since the pressure of the hydraulic pressure supplied to the cylinder 7 is feedback-controlled, the stability is not impaired, and the braking distance can be shortened as described above while maintaining the stability.

The second embodiment of the present invention is shown in FIG. In this embodiment, in the conventional railway vehicle hydraulic brake device shown in FIG. 15, a return conduit 26 from the control valve 6 to the tank 1 is provided.
Is provided with a check valve 28 having a spring 28a for blocking the flow of oil in the direction from the tank 1 to the control valve 6.
a biases the valve element toward the control valve 6.

In this embodiment, the pressure in the cylinder 7 is higher than the atmospheric pressure by the amount corresponding to the urging force of the spring 28a, and bubbles are less likely to be generated in the conduit 22 from the control valve 6 to the cylinder 7. ing.

In the present embodiment, when a command r is sent to the controller 14 in order to reduce the speed, the controller 14 outputs a signal u for setting the control valve 6 to the position (c). As a result, the pressure oil flows through the control valve 6 into the cylinder 7 to increase the cylinder pressure. At this time, as described above, the cylinder pressure before switching is so high that the brake is not applied, and bubbles are unlikely to be generated in the pipe. Therefore, even if the amount of liquid is small, the pressure in the cylinder 7 rises quickly, and compared with the conventional case. The pressure rises quickly. This result is shown in FIG. 5 in comparison with the conventional example. Figure 5
FIG. 5A shows the pressure rising characteristic of the present embodiment, and FIG. As shown in FIGS. 5A and 5B, in this embodiment, the brake start timing t ₁ can be made earlier than in the conventional case.

A third embodiment of the present invention is shown in FIGS. 6 and 7. In this embodiment, the accumulator 5 is eliminated from the second embodiment shown in FIG. 4 and the following device is added. By removing the accumulator 5, the control valve 6 is a two-position system having a position (a) for connecting the pump 2 side to the cylinder 7 side and a position (b) for disconnecting the connection, and the switching valve 3
The 0 positions (x) and (y) are upside down.

Pipe line 22 connecting the control valve 6 and the switching valve 30
An actuator 31 in which a piston 32 is inserted is connected to the piston 32, and the nut 3 is attached to the end of the piston 32.
3 is screwed together, and a gear 34 driven by an electric motor 35 is meshed with a gear provided on the outer periphery of the nut 33, and the gear 34 is rotated by rotating the electric motor 35.
The nut 33 rotates in the direction of the arrow in FIG. 7 via the, and the piston 32 moves in the axial direction (the direction of the arrow in FIG. 7). The electric motor 35 is controlled by a command u _{3 from the} controller 14. Also, pump 2
The relief valve 3 that controls the pressure of the pressure oil discharged from the
₄ is input, the relief valve 3 minimizes the pump discharge pressure when the brake is not operated, and proportional to the magnitude of the brake command r, the relief valve 3 supplies the pressure oil supplied to the cylinder 7 through the control valve 6 and the like. It is designed to increase the pressure.

In this embodiment, when the brake is not operated,
The control valve 6 is in the position (a), the switching valve 30 is in the position (x), and the relief valve 3 minimizes the discharge pressure of the pump 2 as described above. The minimum pressure oil is supplied, the shoe 8 is separated from the friction plate 9, and the brake is not applied.

On the other hand, when the brake is applied, the control valve 6
Is in position (a) and the switching valve 30 is in position (x)
And the set pressure of the relief valve 3 increases in proportion to the magnitude of the brake command r, which increases the pressure of the pressure oil in the cylinder 7 and presses the shoe 8 against the friction plate 9, A braking force proportional to the magnitude of r can be obtained.

When the braking force increases and the slip between the wheel 10 and the rail 11 becomes too large, the wheel 10
Causes abnormal wear and becomes dangerous, so it is necessary to control the braking force so that the slip ratio becomes appropriate. In order to weaken or strengthen the braking force in this way, a volume change caused by reciprocating the piston 22 of the actuator 21 is utilized. That is, during the slip rate control, as shown in FIG. 7, the control valve 6 is set to the position (b) to cut off the communication between the conduits 20 and 22. As a result, the pressure oil conduit 22 from the control valve 6 to the brake cylinder 7 is closed. At this time, if the electric motor 35 is driven by a command from the controller 14 to move the piston 32 of the actuator 31 in the direction of pulling it out, the pressure in the closed chamber, that is, the brake pressure is reduced by ΔP in the following equation.

ΔP = K · Ax / V where K: volumetric elastic coefficient of oil V: volume of oil from the control valve 6 to the brake cylinder 7 x: stroke of the piston 22 A: area of the piston 22 As described above, the slip ratio is calculated from the output of the rotation sensor 12 of the wheel 10 and the cylinder 7
By issuing a command u ₃ to the electric motor 35 to control the rotation of the electric motor 35 so that the pressure (brake pressure) of the pressure oil in the wheel 10 becomes an appropriate value, the pressure of the pressure oil in the cylinder 7 is controlled by the wheel 10. It can be controlled to an appropriate value according to the sliding rate.

On the other hand, the pipeline 25 connected to the second accumulator 18 is a backup line when the pipeline 20, the control valve 6 and the pipeline 22 are damaged or when the power source is down. The valve 30 is in the position (y), and the pressure oil in the second accumulator 18 is supplied to the cylinder 7 to apply the brake. At this time, the control valve 6 takes the position (b), and the conduit 2
0 and 22 are shut off, and the pressure oil in the cylinder 7 is prevented from returning to the tank 1.

As described above, in the present embodiment, the accumulator 5 of the conventional hydraulic system for a railway vehicle shown in FIGS. 14 and 15 can be eliminated to contribute to weight reduction, and the control valve 6, Even if there is a leak in the switching valve 30 or the like, the actuator 31 can set the pressure of the pressure oil in the cylinder 7 to an appropriate value and obtain an effective braking force.

A fourth embodiment of the present invention will be described with reference to FIGS. In this embodiment, the pressure reducing valve 16 is eliminated and the volume cylinder 46 is provided in the conventional railway vehicle hydraulic brake device shown in FIG. Both ends of the volume cylinder 46 are connected to a pipeline 20 from the actuator 5 to the control valve 6 and a pipeline 25 from the accumulator 18 to the switching valve 20, respectively. Further, the piston 46a is built in the volume cylinder 46, and the piston 46a of the volume cylinder 46 is
Volume chambers 46c and 46d that communicate with the conduit 20 and the conduit 25 are formed on both sides of a. Piston 46
The rod 46b of a extends through the inside of the volume chamber 46d to the outside of the volume cylinder 46, and the effective sectional area of the piston 46a on the side of the volume chamber 46c (the area in which the pressure oil in the volume chamber acts on the piston) A ₁ is It is larger than the effective area A ₂ of the volume chamber 46d of the piston 46a.

In this embodiment, the supply of the pressure oil discharged from the pump 2 to the accumulators 5 and 18 and the normal braking action are performed in the same manner as in the conventional hydraulic brake device for railroad vehicles shown in FIG. Further, when pressure oil is normally present in the pipelines 20 and 25 when the brake is not operated, equal pressure oil acts on both sides of the piston 46a, and due to the difference between the effective sectional areas A ₁ and A _{2 on} both sides of the piston 46a. The piston 46a is in contact with the end portion 46e of the volume cylinder 46 on the volume chamber 46d side.

At the time of pre-braking when the pump fails or the control valve 6 malfunctions, the present embodiment operates as follows. That is, at the time of preliminary braking, the pressure of the pressure oil in the conduit 20 decreases due to a failure of the pump, a malfunction of the control valve 6, or the like. This causes a difference in pressure acting on both sides of the piston 46a, and the piston 4a
As shown in FIG. 9, 6a moves to the left side in the figure to move the end portion 46 of the volume cylinder 46 on the volume chamber 46c side.
touch f. As a result, the volume of the volume chamber 46d increases by ΔV = A ₂ · S (S: piston stroke). The pressure P ₁ of the pressure oil in the pipe 25 when the piston 46a moves is P ₁ <A ₂ / A ₁ × P
The relationship of _{1 max} is established. Here, P _{1 max} is the pipeline 25
Is a normal set pressure of, and the value is also a normal set pressure of the conduit 20.

As described above, when the pressure in the pipe 25 is greatly reduced, the volume of the pipe 25 is increased by ΔV, so that the pressure in the pipe 25 is lowered. This pressure drop amount is as shown in the following equation.

ΔP = K · ΔV / V Here, K: bulk modulus of oil of the pipe 25, V: pipe 2
5 volumes.

As described above, the pipeline 20 is
When the pressure oil in the pipeline 25 is used and the pressure oil in the pipeline 25 can no longer be kept, the pressure of the pressure fluid supplied from the pipeline 25 can be lowered by ΔP from the set pressure, which is safe without control by a control valve or the like. It becomes possible to stop the vehicle.

Further, a seal can be attached to the sliding portion of the piston 46a of the volume cylinder 46 so that leakage can be eliminated.

A fifth embodiment of the present invention will be described with reference to FIGS.
It will be explained by 1. This embodiment is the same as the controller 1 in the conventional hydraulic brake system for railway vehicles shown in FIG.
The command of No. 4 is set as follows.

[0059] _{U = K B (r-P} B) where, K _B: control gain r: braking pressure command P _B: control gain K _B of the cylinder pressure above the cylinder pressure as shown in FIG. 10 (a) It is variable so that it is large when P _B is small, and small when P _B is above a certain specified value.

When a command r for braking is issued to reduce the speed, the controller 14 issues a command u for setting the control valve 6 to the position of (c) according to the above equation. As a result, high pressure oil flows through the control valve 6 to the cylinder, but initially the pressure in the cylinder is only the pressure (small) necessary to make the piston rod 7a stroke, and the control gain K _{B at} this time is It has a large value according to FIG. Next, when the shoe 8 at the tip of the piston rod 7a hits the friction plate 9, the pressure in the cylinder begins to rise, but when it exceeds a specified value, the control gain K _B changes to a small value. As described above, when the cylinder pressure P _B approaches the target value, the control gain decreases, so that stability is not impaired.

In the present embodiment, as described above, when a large flow rate of pressure oil is required, the control gain of the controller 14 is increased, and the control gain is decreased during fine pressure control to reduce the brake command r. As shown in FIG. 11, it is possible to shorten the time from when the brake shoe 8 is actuated until the braking action actually starts to be shorter than that of the conventional one, and the pressure gradient when the brake shoe 8 is pressed against the friction plate 9 is reduced to cause vibration. Can be suppressed.

The sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, in the railway vehicle hydraulic brake device shown in FIG. 15, a command to the controller and a command from the controller are as follows.

That is, in this embodiment, the acceleration α _a during acceleration calculated by the speedometer or the accelerometer and the vehicle drive motor current i _a at this time are input to the arithmetic unit 50, and based on this, the following description will be made. A signal of the vehicle body weight ω is output to the controller 14. Further, a desired deceleration β _d is input to the controller 14. The movement of the railway vehicle during acceleration follows the following formula.

[0064]

[Equation 2]

When the acceleration α and the current i of the vehicle driving motor are detected from the equation 2, the weight ω can be calculated as follows.

[0066]

[Equation 3]

On the other hand, the movement of the vehicle during deceleration follows the following formula.

W / g β = T _L + B _P γ ₃ = W γ μ γ ₂ + B _P γ ₃ where β: deceleration _BP : brake pressure γ _2,3 : determined by wheels and reduction ratio Therefore, in order to obtain the deceleration β, the brake pressure B _P is as follows.

[0069]

[Equation 4]

Now, assuming that the number of brake cylinders is n,
In this embodiment, the command r output from the controller 14 is r = B _P / n. This makes it possible to obtain an appropriate braking force according to the vehicle body weight.

Although each of the above embodiments relates to the brake device using pressure oil, the present invention can be applied to the brake device using other fluids such as pressure and water. Further, in each of the above-described embodiments, the brake shoe is brought into contact with the friction plate connected to the wheel to generate the braking force, but instead of this, the brake shoe is used as the wheel or the shaft of the electric motor for driving the wheel. Alternatively, the braking force can be generated by contacting a speed reducer or the like between the electric motor and the wheels.

[0072]

EFFECTS OF THE INVENTION The present invention has the following effects by having the structure provided in each of the claims. (1) According to the present invention described in claim 1, the second control valve is provided in parallel with the control valve for supplying and discharging the pressurized fluid to and from the cylinder,
Supply pressurized fluid to the cylinder after the start of braking, and
Since the supply of the pressurized fluid is shut off when the pressure in the cylinder reaches a predetermined value, the start time of the brake start can be made earlier, thereby shortening the brake distance. (2) According to the present invention as set forth in claim 2, the fluid pressure in the cylinder rises quickly at the beginning of application of the brake, and the brake can be operated without a time delay. It is possible to reliably generate the braking force by suppressing the generation of bubbles inside. (3) According to the present invention as set forth in claim 3, the fluid pressure in the cylinder and hence the braking force can be set to an appropriate value even if there is a leak in the control valve or the like, and the accumulator is eliminated to reduce the weight. Can be achieved. (4) The present invention according to claim 4 is characterized in that, even if the pressure of the pressurized fluid decreases due to damage to the pump line, the control valve, etc.
It is possible to apply a pressurized fluid having an appropriate pressure to the cylinder from the actuator of (1) to apply a safe brake. (5) According to the present invention as set forth in claim 5, the control gain of the controller can be made variable, the time required for the stroke of the piston rod can be shortened, and the brake can be acted in a short time. The pressure gradient can be reduced to suppress the occurrence of vibration. (6) According to the present invention described in claim 6, the vehicle weight can be easily and accurately obtained, and an optimum braking force corresponding to the vehicle weight can be obtained.

[Brief description of drawings]

FIG. 1 is a system diagram of a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of the same embodiment during braking.

FIG. 3 is a characteristic diagram of a conventional railway vehicle hydraulic brake device during braking.

FIG. 4 is a system diagram of a second embodiment of the present invention.

FIG. 5 (a) is a characteristic diagram of brake pressure of the same embodiment, and FIG. 5 (b) is a characteristic diagram of brake pressure of a conventional railway vehicle hydraulic brake device.

FIG. 6 is a system diagram of a third embodiment of the present invention.

FIG. 7 is a system diagram showing the operation of the actuator of the same embodiment.

FIG. 8 is a system diagram of a fourth embodiment of the present invention.

FIG. 9 is a system diagram showing a state at the time of pre-braking when the pressure of the pressure oil in the pipeline 20 of the embodiment has disappeared.

FIG. 10 (a) is a control gain characteristic diagram of the controller of the fifth embodiment of the present invention, and FIG. 10 (b) is a control gain characteristic of the controller of the conventional railway vehicle hydraulic brake device. It is a figure.

11 (b) is a brake pressure characteristic diagram of the same embodiment, and FIG. 11 (a) is a brake pressure characteristic diagram of a conventional railway vehicle hydraulic brake device.

FIG. 12 is a circuit diagram of a fifth embodiment of the present invention.

FIG. 13 is an explanatory diagram of a vehicle body of a conventional railway vehicle.

FIG. 14 is a system diagram of an example of a conventional railway vehicle hydraulic brake device.

FIG. 15 is a system diagram of another example of a conventional hydraulic brake device for a railway vehicle.

[Explanation of symbols]

 1 Tank 2 Pump 3 Relief Valve 4 Check Valve 5 Accumulator 6 Control Valve 7 Cylinder 7a Piston Rod 8 Brake Shoe 9 Friction Plate 10 Wheel 11 Rail 12 Rotation Sensor 13 Pressure Gauge 14 Controller 16 Pressure Reduction Valve 20, 21, 22, 23, 24 , 25, 27 Pipe line 26 Return pipe line 17 Check valve 18 Second accumulator 19 Second control valve 28 Check valve 30 Switching valve 31 Actuator 32 Piston 33 Nut 34 Gear wheel 35 Electric motor 46 Volume cylinder 46a Piston 46c, 46d Volume Room 50 computing machine

Claims (6)

[Claims] 1. A brake shoe connected to a piston rod inserted into a cylinder through which pressurized fluid is supplied and discharged, a pressure gauge for measuring the pressure of pressurized fluid supplied to the cylinder, and a signal from the pressure gauge. In a railway vehicle fluid brake device including a controller to which is input, and a control valve to which a command of the controller is input and which controls supply and discharge of pressurized fluid to and from the cylinder, a brake provided in parallel with the control valve is provided. A railway vehicle fluid brake device comprising: a second control valve that is opened immediately after the start of operation to supply pressurized fluid to the cylinder and is closed when the pressure in the cylinder reaches a predetermined value. 2. A brake shoe connected to a piston rod inserted into a cylinder for supplying and discharging pressurized fluid, a pressure gauge for measuring the pressure of the pressurized fluid supplied to the cylinder, and a signal from the pressure gauge. In a fluid brake device for a railway vehicle, which includes a controller to which is input, and a control valve to which a command of the controller is input to control supply and discharge of pressurized fluid to and from the cylinder, a return line from the control valve to the tank. A fluid brake device for a railway vehicle, characterized in that a check valve for preventing the flow of fluid in the direction from the tank to the control valve is provided in the. 3. A brake shoe connected to a piston rod inserted into a cylinder for supplying and discharging pressurized fluid, a pressure gauge for measuring the pressure of the pressurized fluid supplied to the cylinder, and a signal from the pressure gauge. In a fluid brake device for a railway vehicle, which includes a controller to which is input, and a control valve to which a command of the controller is input and which controls supply and discharge of pressurized fluid to and from the cylinder, a fluid circuit between the control valve and the cylinder. A fluid brake device for a railroad vehicle, comprising means for changing the volume volume of the railcar. 4. A brake shoe connected to a piston rod inserted into a cylinder for supplying and discharging pressurized fluid, a pressure gauge for measuring the pressure of the pressurized fluid supplied to the cylinder, and a signal from the pressure gauge. In a fluid brake device for a rail vehicle equipped with a controller to which is input, and a control valve to which a command of the controller is input and which controls supply and discharge of pressurized fluid to and from the cylinder, pressurization to the cylinder via the control valve A pressurized fluid accumulator capable of supplying fluid, a second accumulator capable of supplying pressurized fluid to the cylinder, a switching valve for selectively connecting one of the accumulator and the second accumulator to the cylinder, and Both ends of a conduit from the accumulator to the cylinder and a conduit from the second accumulator to the cylinder A fluid brake device for a railway vehicle, comprising a volume cylinder that is connected to a piston and has a built-in piston. 5. A brake shoe connected to a piston rod inserted into a cylinder for supplying and discharging pressurized fluid, a pressure gauge for measuring the pressure of the pressurized fluid supplied to the cylinder, and a signal from the pressure gauge. In a railway vehicle fluid brake device including a controller to which is input, and a control valve to which a command of the controller is input and which controls supply and discharge of pressurized fluid to and from the cylinder, a control gain of the controller is set to a cylinder pressure. A fluid brake device for a railway vehicle, which is variable so as to decrease when increasing. 6. A railway vehicle brake characterized in that a vehicle body weight is obtained from an acceleration calculated by an accelerometer or a speedometer and a current flowing through a vehicle drive motor, and a braking force corresponding to the vehicle body weight is generated. Control method.