JPH0379218B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a multistage relay valve that is used in a digital electric command type air brake system for railway vehicles and outputs air at a pressure according to a brake command consisting of a digital electric signal. [Prior Art] As a conventional example of this type of multi-stage relay valve, pages 46 to 49 (especially the figure 3 and FIG. 4), which is shown in FIG. 7 and will be described below. In FIG. 7, MV1, MV2, and MV3 are all the first solenoid valves that are always deenergized, EBV is the second solenoid valve that is always energized, and DRV is the solenoid valves MV1 to MV3,
This is a multi-stage relay valve that outputs air at a pressure that corresponds to the EBV excitation/demagnetization, or brake command consisting of a digital electric signal. The first solenoid valves MV1, MV2, and MV3 all have the same configuration, and are connected to the variable load valve via the first throttle NV1.
An air supply port a connected to the output side of the VLV, an air supply and exhaust port b connected to the first control chambers C1, C2, and C3 of the multistage relay valve DRV, respectively, and an exhaust port Ex opened to the atmosphere. In the demagnetized state shown in the figure, the supply/discharge port b is cut off from the air supply port a, and the supply/discharge port b is communicated with the exhaust port Ex. When energized, the supply/discharge port b is cut off from the exhaust port Ex. and communicates the air supply port a with the air supply and discharge port b. The second solenoid valve EBV is connected to an air supply port a connected to the output side of the variable load valve VLV through a second throttle NV2 having a larger diameter than the first throttle NV1, and to a second control room C4 of the multistage relay valve DRV. It has a connecting supply and exhaust port b and an exhaust port Ex that is open to the atmosphere, and in the illustrated excited state, the supply and discharge port b is cut off from the air supply port a, and the supply and discharge port b is connected to the exhaust port Ex. When communicated and demagnetized, the air supply/exhaust port b is cut off from the exhaust port Ex, and the air supply/exhaust port a is communicated with the air supply/exhaust port b. The multi-stage relay valve DRV includes an air supply chamber D connected to the pressure air source MR, an output chamber F connected to the brake cylinder BC, and an exhaust chamber E open to the atmosphere.
A balancing chamber C5 communicating with the output chamber F, and the second
It is divided into a control room C4 and first control rooms C1 to C3. A first partition wall G that partitions the air supply chamber D and the output chamber F.
There is an air supply hole H in the center that communicates these two chambers D and F.
is formed, and a valve seat I is provided protrudingly around the air supply chamber D side of this air supply hole H, and the air supply valve K, which is biased by a weak return spring J in the direction of seating on this valve seat I, opens into the air supply chamber. It is located inside D. A hollow exhaust valve rod M is inserted into the second partition L that partitions the output chamber F and the exhaust chamber E so as to be slidable in an airtight manner.
Its tip loosely fits into the air supply hole H and faces the air supply valve K, and one side opens at the tip and the other opens into the exhaust chamber E. A second connecting rod N is fixed to the center of the balancing and second control piston S4 that partitions the balancing chamber C5 and the second control chamber C4.
It passes through the third partition Q that partitions the balance chamber C5 and the balance chamber C5 in an airtight slidable manner, and its tip is connected to the exhaust valve stem M. Note that a weak return spring R is provided between the piston S4 and the third partition Q, and has a biasing force in a direction (downward in the figure) that moves the exhaust valve rod M away from the intake valve K. The first control pistons S1, S2, and S3 partition the second control chamber C4 and the first control chambers C1 to C3, respectively, and are opposed to each other and arranged in a stacked manner.
They are connected to each other by a connecting rod T, and the tip of this first connecting rod T is located inside the second control chamber C4.
It can freely come into contact with and separate from the connecting rod N. Table 1 outlines the operation of the multistage relay valve DRV with the above configuration. In Table 1, the notch indicates the stage of the brake command, and each solenoid valve MV1~
"1" in MV3 and EBV means excitation and "0" means demagnetization, which corresponds to the brake command. In addition, the effective area ratio of the pistons S1 to S4 is S
4:S1:S2:S3=9:7:6:4 The output air pressure level is shown.

[Problem that the invention seeks to solve]

Recently, with the plan to increase the speed of trains on conventional lines, there has been a demand for increasing the output air pressure of the air brake device equipped with the above-mentioned multi-stage relay valve. Furthermore, depending on the friction characteristics of the brake shoes, it is possible that the output air pressure may be reduced.
Therefore, a possible solution to these demands is shown in FIG. 8. However, FIG. 8 is not publicly known. In FIG. 8, S20 is a control piston attached to the bottom wall U side, and this control piston S20 partitions two control chambers C21 and C22. Then, one control room C21 is opened to the atmosphere and the output air of the variable load valve VLV is introduced into the other control room C22 to increase the pressure, and the other control room C22 is opened to the atmosphere and One control room C21
The pressure is reduced by introducing the output air of the variable load valve VLV into the air. However, when using the above means, there are the following problems. First, when increasing the pressure, assuming that the effective area ratio of the control piston S20 is 1, the output pressures in Table 1 above are: 1 notch (0), 1 notch (2/9), 2 notches (3/9), 3 notch (4/9), 4 notch (5/
9), 5 notches (6/9), 6 notches (7/9),
7 notches (8/9), 8 notches (9/9), emergency (9/9). That is, in this case, although the pressure can be increased when a service brake command is issued for 1 to 7 notches, the pressure increase is a constant amount (1/9) for any notch, and there is a problem that a proportional pressure increase cannot be obtained. Furthermore, when attempting to reduce the pressure, if the effective area ratio of the control piston S20 is 1 as described above, then the first
The output pressures in the table are 1-notch (0), 1-notch (0), and 2-notch (0).
Notchi (1/9), 3 Notchi (2/9), 4 Notchi (3/9), 5 Notchi (4/9), 6 Notchi (5/9)
9), 7 notches (6/9), 8 notches (9/9),
Emergency (9/9). That is, in this case, although the pressure can be reduced when the service brake command is issued for 1 to 7 notches, the pressure reduction is a constant amount (1/9) for all notches, and there is a problem that a proportional pressure increase cannot be obtained. [Means for solving the problems] Therefore, the means of the present invention for solving the above problems are as follows.
In the conventional multi-stage relay valve as shown in FIG. 7, the effective area on which the output air acts as a balancing force on the balancing piston is switched between a normal first area and a second area that is larger or smaller than the normal first area. It was configured as follows. [Operations and Effects] According to the above means of the present invention, the first area of the balancing piston is A1, the second area is A2, and the effective area where air pressure acts on the control piston as a command force is B, and B acts on the control piston. Set the command air pressure to P1,
If the output air pressure when the first area A1 is P21, and the output air pressure when the second area A2 is P22,
When switching to the normal first area A1, P21×A1=
Since P1×B holds true, output air pressure P21=(B/
A1)×P1, and when switching to the second area A2, P22×A2=P1×B holds, so the output air pressure P22=(B/A2)×P1. Here, if A1>A2 is set, P21<
P22, and by switching to the small second area A2, the output air pressure can be adjusted for any brake command.
It is possible to increase the pressure of P22 more than the normal P21,
Moreover, since the effective area B changes according to the brake command, the pressure increase is a proportional pressure increase. Also, if you set A1<A2, P21>P22,
By switching to the larger second area A2, the output air pressure P22 can be reduced from the normal P21 for any brake command, and since the effective area B changes according to the brake command. ,
The pressure reduction becomes a proportional pressure reduction. [Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 6. Components that are the same as those in the conventional example are given the same reference numerals as in FIG. 7, and their explanation will be omitted. FIG. 1 shows a first embodiment (pressure increase type), which differs from the conventional example shown in FIG.
, and the balancing chamber C6 on one side is always communicated with the output chamber F, and the balancing chamber C5 on the other side is connected to the output chamber F via the third solenoid valve MV5. The area ratio of the pistons S4 and S5 is set to S4:S5=9:6, and
The area ratio of the first control pistons S1 to S3 is the same as in the conventional example, and is S1:S2:S3=7:6:4. The above-mentioned third solenoid valve MV5 normally switches pressure increase, and is connected to the output chamber F via the third throttle NV3.
It has an air supply port a connected to the above balance chamber C5, an air supply/exhaust port b communicating with the above-mentioned balancing chamber C5, and an exhaust port Ex opened to the atmosphere. isolates supply/discharge port b from exhaust port Ex and communicates air supply/discharge port a with supply/discharge port b, and when excited, switches from the state shown in Figure 1 and connects supply/discharge port b to supply/discharge port B. It is shut off from the port a, and the supply/discharge port b is communicated with the exhaust port Ex. In other words, when the third solenoid valve MV5 is demagnetized, the two balancing chambers C5 and C6 communicate with the output chamber F, so the effective area (first area) where the output air pressure acts as a balancing force is 9, and when the third solenoid valve MV5 is excited, one of the balancing chambers C5 is opened to the atmosphere, so the effective area (second area) where the output air pressure acts as a balancing force is cut to 6. Change. This third solenoid valve MV5 is energized when the running speed of the train exceeds a high-speed first set value (for example, 110 km/h), and when the running speed of the train exceeds a low-speed second set value (for example, 40 km/h) due to brake operation, etc. h) It is set to demagnetize when the voltage drops below. In the first embodiment shown in FIG. 1 above, the third solenoid valve
The operation when MV5 is demagnetized is the same as that shown in FIG. 7 and as shown in Table 1 above. Furthermore, the operation when the third solenoid valve MV5 is excited is basically the same as shown in Fig. 7, but the increased output air pressure is 1 notch (1/6), 2 notches (2/6). ,3
Notchi (3/6), 4 Notchi (4/6), 5 Notchi (5/6), 6 Notchi (6/6), 7 Notchi (7/
6), 8 notches (9/6), and emergency (9/6). In addition, each solenoid valve MV1 in the above first embodiment
~It is optional whether MV3, MV5, and EBV are set to a constantly demagnetized type or a constantly energized type. Also, change the setting position of the third throttle NV3 to the third solenoid valve.
It can also be used as the MV5 exhaust port Ex or supply/exhaust port B.
You can delete this. Furthermore, the area ratio of each piston S1 to S5 may be changed as necessary. FIG. 2 shows a second embodiment (decompression type), and the difference from the first embodiment shown in FIG. 1 is that the balance piston S
4. The area ratio of S5 is set to S4:S5=9:11, and other aspects are the same as in FIG. Therefore, in this second embodiment, when the third solenoid valve MV5 is excited, the reduced output air pressure is 1 notch (1/11), 2 notches (2/11), and 3 notches (3 notches). /11), 4 notch (4/
11), 5 notches (5/11), 6 notches (6/11),
7 notches (7/11), 8 notches (8/11), and emergency (9/11). FIG. 3 shows a third embodiment (pressure increase type), and the difference from the first embodiment shown in FIG. 1 is that the balance piston S
A fourth partition wall V is provided between S4 and S5, and this fourth partition wall V
and the piston S4 are set as one balancing chamber C5, the space between the fourth partition wall V and the balancing piston S5 is opened to the atmosphere, and the space between the balancing piston S5 and the fourth partition wall Q is set as one balancing chamber C5. chamber C6, and these balancing chambers C5,
C6 is a 4-port, 2-position, constantly energized fourth solenoid valve.
It is connected to output room F via MV6. Since this fourth solenoid valve MV6 is normally excited, it is switched to the first position (a), communicating the output chamber F with one balancing chamber C5 and the other balancing chamber C6 with the atmosphere. When the pressure is increased, it is demagnetized and returns to the second position (b), communicating the output chamber F with the balance chamber C6 and opening the balance chamber C5 to the atmosphere. The other configurations and operations of the third embodiment shown in FIG. 3 are the same as those shown in FIG. 1, so their explanations will be omitted. FIG. 4 shows a fourth embodiment (pressure increase type), which is different from the first embodiment shown in FIG. This is because the area ratio of the balancing pistons S6 and S5 is S6:S5=3:6, and other explanations will be omitted. FIG. 5 shows a fifth embodiment (decompression type), and the difference from the second embodiment shown in FIG. 2 is that the balance piston S
6 and a fourth partition wall V are additionally provided, S4 is dedicated to the control piston, and the area ratio of the balancing pistons S6 and S5 is set to S6:S5=2:11, and other explanations will be omitted. FIG. 6 shows a sixth embodiment (decompression type), and the difference from the fifth embodiment in FIG. 5 is that the balance piston S
6 and the fourth partition wall V are opposite to each other, the area ratio of the balancing pistons S6 and S5 is S6:S5=2:9, and the balancing chamber C5 is normally open to the atmosphere.
This is because the output air pressure is introduced into the balance chamber C5 when the pressure is reduced, and other explanations will be omitted.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the first embodiment (pressure increasing type) of the present invention, Fig. 2 is an explanatory diagram of the second embodiment (pressure reducing type), and Fig. 3 is an explanatory diagram of the third embodiment (pressure increasing type) of the present invention. ), FIG. 4 is an explanatory diagram of the fourth embodiment (pressure increase type), FIG. 5 is an explanatory diagram of the fifth embodiment (decreasing pressure type), and FIG. 6 is an explanatory diagram of the sixth embodiment (pressure reduction type). FIG. 7 is an explanatory diagram of a conventionally known example, and FIG. 8 is an explanatory diagram of another conventional example (not publicly known). DRV...Multi-stage relay valve, MR...Pressure air source, BC...
Brake cylinder, D...air supply chamber, E...exhaust chamber, F
...output chamber, H...air supply hole, I...valve seat, J...return spring, K...air supply valve, M...exhaust valve rod, R...return spring,
S1, S2, S3...first control piston, S4...control (balance and second control) piston, S5, S6...balance piston.

Claims (1)

[Scope of Claims] 1. An air supply chamber connected to a pressure air source, an output chamber connected to a brake cylinder, an exhaust chamber open to the atmosphere, and an air supply hole communicating the air supply chamber with the output chamber. a valve seat protruding around the air supply chamber side, an air supply valve biased by a spring so as to be seated on the valve seat, and a valve with its tip facing the air supply valve and floating through the air supply hole. A hollow exhaust valve rod that is fitted and has one opening at its tip and the other opening into the exhaust chamber, and receives pressurized air in response to a brake command consisting of a digital electric signal to move the exhaust valve rod toward the air supply valve. It includes a plurality of control pistons that receive a command force for movement, and a balance piston that receives pressurized air in the output chamber and receives a balancing force that opposes the command force, and outputs air at a pressure according to the brake command. In a multi-stage relay valve for a railway vehicle, the effective area on which the output air acts as a balancing force on the balancing piston is configured to be switched between a normal first area and a second area that is larger or smaller than the normal first area. Features: Multi-stage relay valve for railway vehicles.