JPH0417413Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is an automatic air brake system for railway vehicles, in which the brake pipes of the entire train are connected from a pressure-increasing relay valve installed in the leading car of a locomotive. Automatic air brakes for railway vehicles that are used to gradually reduce the pressure in the brake pipe to a predetermined pressure so that the brake control valve connected to the brake pipe does not operate the brake after increasing the pressure above the predetermined pressure according to the command. Regarding equipment.

[Prior art] Previously, Utility Application No. 62-65013 related to the applicant's earlier application
(Brake valve device), which will be explained below based on FIGS. 5 and 6.

FIG. 5 shows a state in which the brake valve BV is operated and the switching valve TV is switched to the pressure increasing position B.

At this time, the brake valve BV closes its discharge port Ex and transfers the pressure air from the original air reservoir pipe MRP to the balancing air reservoir.
Supplies the ER and relay valve RV to the first pilot chamber A1, and operates them (pilot command).
It is pressurized to a predetermined pressure according to the

In addition, when the switching valve TV is in the pressure increasing position B, it supplies pressurized air from the pressure regulating valve (pressure reducing valve) PRV to the volumetric air reservoir VR and the second pilot chamber A2 for pressure increasing of the relay valve RV. the pressure regulating valve
Pressurizing to the PRV set pressure.

By pressurizing both pilot chambers A1 and A2,
The relay valve RV increases the pressure of the brake pipe BP higher than a predetermined pressure and maintains the pressure. This holding state is generally called overlapping, and the air supply valve C is seated on the air intake valve seat D with the hollow exhaust valve stem B still in contact with it, and the force pushing the balance piston E from above and below as shown in the figure is It's balanced. At this time, the air supply chamber F connected to the original air reservoir pipe MRP, the output chamber G connected to the brake pipe BP, and the exhaust chamber H opened to the atmosphere are closed. Note that the tip of a push rod J whose base is fixed to the pressure booster piston 1 is in contact with a push rod K that connects the balance piston E and the exhaust valve rod B.

By increasing the pressure in the brake pipe BP higher than the predetermined pressure according to the above-mentioned discharge command, the brake control valve CV of the rear vehicle of the train is also operated, and the brake cylinder BC is completely exhausted. . In the figure, SR is a supply air reservoir and CR is a constant pressure air reservoir.

After draining the brake cylinder BC of the rear vehicle, the brake pipe BP, which has been pressurized excessively, is depressurized to a predetermined pressure. At this time, if the brake pipe BP pressure reduction speed exceeds the standard pressure reduction speed, the brake control valve
In order to re-activate the brake and supply air to the brake cylinder BC, the second pilot chamber A of the relay valve RV
2. Gradually reduce the pressure.

That is, when the switching valve TV is returned to the pressure reducing position A at time t1, the pressurized air in the volumetric air reservoir VR and the second pilot chamber A2 is discharged into the atmosphere through the restriction NV2, and the air pressure is as shown in Fig. 6. It gradually decreases as shown. Note that the slope of the straight line shown by the dashed line in FIG. 6 corresponds to the reference pressure reduction speed.

Due to this pressure reduction in the second pilot chamber A2, in the relay valve RV, the pressure increase piston 1 and the push rod J
The force that pushes the balance piston E upward in the figure decreases through The pressure is reduced through the hollow part of the exhaust valve stem B and the exhaust chamber H.

Then, when the pressure reduction in the second pilot chamber A2 is completed and the pressure in the output chamber G, that is, the brake pipe BP is reduced to a predetermined pressure, the relay valve RV returns to the overlapping state again.

[Problem that the invention attempts to solve]

The pressure reduction in the second pilot chamber A2 is restricted to NV2.
Since the pressure reduction is performed via The speed decreases, and as a result, there is a problem in that it takes a long time to reduce the pressure in the brake pipe BP to a predetermined pressure.

[Means for solving problems]

Therefore, the purpose of this invention is to shorten the time required to reduce the pressure of the brake pipe BP to a predetermined pressure, and the technical means for this purpose is to control the brake that operates based on the pressure difference between the brake pipe and the constant pressure air reservoir. valve and
A brake valve that pressurizes the balance air reservoir by operating the handle and reduces the pressure of the balance air reservoir by operating the brake, and a first pilot chamber and a switching valve connected to the balance air reservoir to supply or exhaust a predetermined pressure. An automatic braking system for a railway vehicle, which has a second pilot chamber in which the pressure is applied, and a relay valve that pressurizes and depressurizes the brake pipe based on pressurized air supplied to the first pilot chamber or the second pilot chamber, The present invention is characterized in that an exhaust throttle device having a pressure reducing valve and a throttle connected to the output side of the pressure reducing valve is provided on the exhaust side of the switching valve.

[Effect]

According to the above means, the exhaust air for reducing the pressure in the second pilot chamber is lowered to a constant pressure by the pressure reducing valve and then exhausted through the throttle, so that the pressure air exhausted from the throttle is The exhaust speed becomes constant, and the air pressure in the second pilot chamber can be reduced linearly along the reference pressure reduction speed.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. Components that are the same as those in the conventional example are designated by the same reference numerals as in FIG. 5, and their explanation will be omitted.

FIG. 1 shows a first embodiment of an exhaust throttle device and an example of its use.

The exhaust throttle device 1 connects to the relay valve via the switching valve TV.
Primary room 2 connected to RV's second pilot room A2
, a secondary chamber 3 connected to the exhaust side, a valve seat 5 protruding around the primary chamber 2 side of the exhaust hole 4 that communicates both chambers 2 and 3, and a valve seat 5 in the direction in which the valve seat 5 is seated ( A valve member 7 is provided in the primary chamber 2 and is urged downward (in the downward direction in the figure) by a weak return spring 6, and a pressure regulating spring 8 is movably provided with one side facing the secondary chamber 3.
A piston 9 with a membrane plate that receives a biasing force in the direction of the secondary chamber 3 (upward in the figure) by
The pressure reducing valve 1A is composed of a push rod 10 whose base is fixed to the valve member 7 and whose tip end is loosely fitted into the exhaust hole 4 and faces the valve member 7, and a throttle NV1 connected to the secondary chamber 3 of the pressure reducing valve 1A. vinegar. In addition, the pressure reducing valve 1A
A return chamber 11 communicating with the secondary chamber 3 is formed behind the valve member 7, and the effective cross-sectional area of the return chamber 11 is the same as the effective cross-sectional area of the valve seat 5, and the valve member 7 is kept in pressure balance. I'm letting you do it.

FIG. 1, like FIG. 5, shows a state in which the brake valve BV is operated and the switching valve TV is set to the pressure increasing position B.

At this time, the relay valve RV, brake pipe BP, brake control valve CV, etc. are the same as in FIG. 5.

Further, in the pressure reducing valve 1A, the piston 9 moves upward in the figure due to the urging force of the pressure regulating spring 8, and the push rod 10 pushes the valve member 7 widely open, so that the primary chamber 2 and the secondary chamber 3 are Both are at atmospheric pressure.

In the state shown in FIG. 1, the switching valve
When the TV returns to the reduced pressure position A, the volumetric air reservoir
Pressure air in VR and second pilot chamber A2 is
It flows out to the exhaust throttle device 1, passes through its primary chamber 2 and exhaust hole 4, and reaches the secondary chamber 3, pressing the piston 9 downward in the figure, and as shown in FIG. to maintain the pressure air in the secondary chamber 3 at a constant pressure. At the same time, the pressure air in the secondary chamber 3 is restricted to NV
1 is emitted into the atmosphere.

Therefore, a constant pressure is supplied to the throttle NV1, and exhaust from the throttle NV1 is performed at a constant speed, and the secondary chamber 3 and the throttle NV1 are exhausted.
Since the pressurized air in the second pilot chamber A2 is flowing out, the pressure reduction rate in the second pilot chamber A2 becomes constant, and the pressure in the second pilot chamber A2 is linearly reduced as shown by the solid line in FIG.

Then, the pressure reduction in the second pilot chamber A2 progresses, and at time t2, when the air pressure becomes lower than the set pressure of the pressure reducing valve 1A, the valve member 7 of the pressure reducing valve 1A is fully opened as shown in FIG. The exhaust (depressurization) speed decreases and linearity is lost.

However, until the time t2 when this linearity is lost, the pressure is reduced linearly along the standard pressure reduction speed, so compared to the conventional example, the time required to return the brake pipe BP to the predetermined pressure is greatly shortened. Ru.

Fig. 4 shows a second embodiment, which differs from the first embodiment in that the return chamber 11 of the pressure reducing valve 1A is omitted, and the same reference numerals as in Fig. 1 are used to omit the explanation. do.

Note that according to this second embodiment, the first
Although the linearity during depressurization is slightly inferior compared to the example,
It has been confirmed through experiments that the decompression time can be shortened compared to the conventional example shown in FIG.

Further, the aperture NV1 shown in the first and second embodiments may be a variable aperture.

〔effect〕

As shown in the above embodiments, according to the present invention, the second relay valve of the automatic braking device for railway vehicles
Since the air pressure in the pilot chamber can be reduced linearly along the reference pressure reduction speed, the pressure reduction time required to return the brake pipe to a predetermined pressure can be shortened.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the first embodiment and usage example of the present invention, Fig. 2 is an explanatory diagram of the operation of the first embodiment, and Fig. 3 is an explanatory diagram of the first embodiment of the present invention.
FIG. 4 is an explanatory diagram of the characteristics of the first embodiment of the present invention, FIG. 4 is an explanatory diagram of the second embodiment of the present invention, FIG. 5 is an explanatory diagram of the conventional example, and FIG. 6 is an explanatory diagram of the characteristics of the conventional example. . 1... Exhaust throttle device, 1A... Pressure reducing valve, NV1
...Restriction, BP...Brake pipe, CR...Constant pressure air reservoir, ER...Balancing air reservoir, RV...Relay valve, A1
...First pilot chamber, BV...Brake valve, A2
...2nd pilot room, TV...switching valve.

Claims (1)

[Scope of Claim for Utility Model Registration] A brake control valve that operates based on the pressure difference between the brake pipe and the constant pressure air reservoir, pressurizes the balance air reservoir by operating the handle, and depressurizes the balance air reservoir by operating the brake. a first pilot chamber connected to the balancing air reservoir and a second pilot chamber to which a predetermined pressure is supplied or exhausted by the switching valve, and a predetermined pressure is supplied to or exhausted from the first pilot chamber or the second pilot chamber. The automatic braking system for railway vehicles is equipped with a relay valve that increases or decreases the pressure of the brake pipe based on the pressurized air. An automatic braking device for a railway vehicle, characterized in that an exhaust throttle device is provided.