JPH0355481Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is used in an automatic air brake system for railway vehicles, and is used in automatic air brake systems for railway vehicles. This invention relates to a three-pressure control valve that outputs air at a high pressure.

[Conventional technology]

As a conventional example of this type of control valve,
There is one disclosed in Japanese Patent No. 19866, which is shown in FIG. 3 and will be explained below.

In Fig. 3, 1 is an air supply chamber connected to the pressure air source SR, 2 is an output chamber connected to the brake cylinder BC, 3 is an exhaust chamber open to the atmosphere, and 4 is in communication with the output chamber 2. Balancing chamber, 5 is an atmospheric chamber open to the atmosphere, 6 is a brake pipe chamber connected to the brake pipe BP, 7 is a constant pressure chamber connected to the constant pressure air reservoir CR, CHV is the brake pipe BP and constant pressure air reservoir CR
This is a check valve that connects the brake pipe with the brake pipe BP in the opposite direction.

The first partition wall 21 that partitions the air supply chamber 1 and the output chamber 2 is provided with an air supply hole 8 that communicates the two chambers 1 and 2, and a valve is provided around the air supply hole 8 on the air supply chamber 1 side. A seat 9 is provided in a protruding manner, and the air supply valve 10 is urged by a weak return spring 11 so as to be seated on this valve seat 9.

A hollow exhaust valve rod 12 is fitted into the second partition wall 22 that partitions the output chamber 2 and the exhaust chamber 3 in an airtight manner, and its tip loosely fits into the air supply hole 8 and connects to the air supply valve 10. They face each other, one opening at the tip and the other opening into the exhaust chamber 3.

A connecting rod 14 is fixed to the center of the balancing piston 13 that partitions the balancing chamber 4 and the atmospheric chamber 5, and one side of the connecting rod 14 connects the exhaust chamber 3 and the balancing chamber 5.
The exhaust valve rod 12 is connected to the exhaust valve rod 12 by passing through the third partition wall 23 that partitions the exhaust valve rod 12 in an airtight slidable manner.

The other end of the connecting rod 14 passes through a fourth partition wall 24 that partitions the atmospheric chamber 5 and the brake pipe chamber 6 in an airtight manner, and a control piston 15 that partitions the brake pipe chamber 6 and the constant pressure chamber 7. is connected to the center of the Note that the control piston 15 has a weak return spring 1.
It is receiving a biasing force of 6.

Figure 3 shows that the brake pipe BP is at a predetermined pressure (for example,
5 kg/cm ² ), and at this time, the constant pressure air reservoir CR is also at a predetermined pressure, and the control piston 15 is moving downward in the figure by the urging force of the return spring 16. For this reason, the air supply valve 10 is
The tip of the exhaust valve rod 12 is separated from the air supply valve 10.

Therefore, in the relaxed state shown in Figure 3,
The output chamber 2 and the balance chamber 4 communicate with the exhaust chamber 3, and the brake cylinder BC is at atmospheric pressure.

In this wet state, when the pressure in the brake pipe BP is reduced by the brake operation of the brake valve (not shown), the control piston 15 moves upward in the figure in response to the command force based on the amount of pressure reduction. Since the exhaust valve rod 12 also moves upward, its tip opening first comes into contact with the air supply valve 10 and closes it, and then moves upward to displace the air supply valve 10 from the valve seat 9, thereby opening the air supply chamber 1 and the air supply valve 10. Air is supplied to the brake cylinder BC through the air hole 8 and the output chamber 2. This is called air supply operation.

Along with this air supply operation, the air pressure in the balancing chamber 4 also rises, and the balancing piston 13 that receives this pressure receives a downward balancing force in the figure that opposes the command force, and the balancing force increases. When the above command force is almost balanced,
Air supply valve 10 with the tip of exhaust valve rod 12 in contact with it
is seated on the valve seat 9, and the output air pressure at that time is maintained. This is called overlap.

The relationship between the command force and the balance force in this overlapping state is expressed by the following equation. However, P is the specified pressure, P1 is the reduced brake pipe BP pressure, P2
is the output air pressure, S1 is the effective area of the control piston 15, S2 is the effective area of the balancing piston 13,
The biasing force of the return spring 16 is extremely small and is ignored.

P2×S2=(P-P1)×S1...(1) Therefore, the output air pressure P2 is P2=(S1/S2)×(P-P1)...(2) It is proportional to the amount of pressure reduction in the brake pipe BP.

In the above overlapped state, if the brake valve (not shown) is operated to pressurize the brake pipe BP, the right side (command force) of the above equation (1) becomes smaller than the left side (balanced force), so the control piston 15, The balance piston 13 and the exhaust valve rod 12 move downward in the figure, the tip of the exhaust valve rod 12 separates from the air supply valve 10, and the brake cylinder BC is exhausted. This is called exhaust operation.

Then, when the brake pipe BP is pressurized to a predetermined pressure, it returns to the relaxed state shown in FIG. 3.

[Problem that the invention attempts to solve]

Recently, with plans to increase the speed of vehicles such as locomotives on conventional lines, there has been a demand for increasing the output air pressure of the air brake device equipped with the above-mentioned three-pressure type control valve. Furthermore, in the case of air brake systems for special small vehicles such as trolley cars, it is also conceivable to reduce the output air pressure using the same control valve as in the past.

However, until now, there has been no three-pressure control valve itself that satisfies the above requirements, and for this reason, the applicant's earlier application, Utility Application No. 1982-92982 (1982
The solenoid valve disclosed in Figure 3 of the application filed on June 17, 2013
Although it has been considered to combine the AMV and the relay valve RV on the output side of the conventional three-pressure control valve, this is not preferable because it increases the size of the air brake device.

[Means for solving problems]

Therefore, the present invention aims to provide a three-pressure control valve with a pressure increasing or decreasing function.
The technical means is that, in the conventional three-pressure control valve, the effective area on which the output air acts as a balancing force on the balancing piston is divided into a normal first area and a second area that is larger or smaller than the normal first area. This is because the system is configured to switch to .

[action, effect]

According to the above means of the present invention, the first area of the balancing piston is S2, the second area is S3, the effective area of the control piston is S1, the brake pipe pressure (predetermined pressure) at the time of unloading is P, and the brake pipe pressure (predetermined pressure) at the time of braking is Assuming that the reduced brake pipe pressure is P1, the output air pressure when the first area S2 is P21, and the output air pressure when the second area S3 is P22, (a) In the case of the normal first area S2. , P21×S2=(P-P1)×S1 holds, so P21=(S1/S2)×(P-P1), (b) When switching to the second area S3, P22×S3=(P- Since P1)×S1 holds, P22=(S1/S3)×(P−P1).

Here, if S2>S3 is set, then P21<P22, and by selecting a small second area S3, the output air pressure P22 can be increased from the normal pressure P21.

Also, on the contrary, if you set S2<S3,
P21>P22, and by switching to the larger second area S3, the output air pressure P22 can be made lower than the normal P21.

Therefore, according to the present invention, by switching the effective area on which the output air pressure acts on the balance piston to a small or large area, the three-pressure control valve itself can increase its output air pressure from the normal output pressure. Pressure or pressure can be reduced, and there is no need to combine another relay valve or the like on the output side.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on FIGS. 1 and 2. Components that are the same as those in the conventional example are designated by the same reference numerals as in FIG. 3, and their explanation will be omitted.

FIG. 1 shows a first embodiment (pressure increase type), which is different from the conventional example shown in FIG. , the balancing chamber 18 on one side is always communicated with the output chamber 2, and the balancing chamber 4 on the other side is connected to the solenoid valve 1.
9 to the output chamber 2. Note that, when the effective areas of the balancing pistons 13 and 17 are respectively S2 and S3, S2>S3.

The solenoid valve 19 normally switches the pressure increase, and has an air supply port a connected to the output chamber 2, an air supply/discharge port b connected to the balancing chamber 4, and an exhaust port c open to the atmosphere. It is a constant demagnetizing type, and when demagnetizing as shown in FIG. 1, the exhaust port c is blocked and the air supply port a
communicates with the supply/discharge port b, and when excited, the first
Switching from the state shown in the figure, the air supply port a is shut off and the air supply and discharge port b is communicated with the exhaust port c.

That is, when the solenoid valve 19 is demagnetized,
Since the two balancing chambers 4 and 18 communicate with the output chamber 2, the output air pressure substantially acts as a balancing force only on one of the balancing pistons 13, and its effective area (first area) is S2, and when the solenoid valve 19 is excited, one of the balancing chambers 4 is opened to the atmosphere, so the output air pressure acts as a balancing force only on the other balancing piston 17. Its effective area (second area) is S3 (however, S2>
S3).

Therefore, in this first embodiment, the operation when the solenoid valve 19 is demagnetized is substantially the same as in FIG. 3, and the operation when the solenoid valve 19 is energized is basically the same. However, the output air pressure is increased.

The solenoid valve 19 is energized when the running speed of the vehicle exceeds a high speed first set value (for example, 110 km/h), and when the running speed exceeds a low speed second set value (for example, 40 km/h) due to brake operation or the like. It is set to demagnetize when the value falls below.

Further, it is optional to change the electromagnetic valve 19 to a constantly excited type.

FIG. 2 shows a second embodiment (decompression type), and the difference from the first embodiment shown in FIG. 1 is that the balance piston 1
The difference is that the relationship between the effective area S2 of the balance piston 17 and the effective area S3 of the balance piston 17 is set to S2<S3, and the other points are the same as in FIG.

Therefore, in this second embodiment, during normal times when the solenoid valve 19 is demagnetized, the output air pressure substantially acts as a balancing force only on one balancing piston 13, and its effective area (the 1 area) is S2, and when the solenoid valve 19 is excited,
The output air pressure acts as a balancing force only on the other balancing piston 17, and its effective area (second
(area) becomes S3 (where S2<S3), and the output air pressure is lower than normal.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a first embodiment (pressure increasing type) of the present invention, FIG. 2 is an explanatory diagram of the second embodiment (depressurizing type), and FIG. 3 is an explanatory diagram of a conventional example. BC...brake cylinder, BP...brake pipe, CR...constant pressure air reservoir, CHV...check valve, SR
... Pressure air source, 1 ... Air supply chamber, 2 ... Output chamber,
3... Exhaust chamber, 4... Balance chamber, 6... Brake pipe chamber, 7... Constant pressure chamber, 8... Air supply hole, 9... Valve seat,
10...Air supply valve, 11...Return spring, 19...Solenoid valve, 12...Exhaust valve rod, 13...Balancing piston, 15...Control piston, 16...Return spring,
17...Balance piston, 18...Balance chamber.

Claims (1)

[Claims for Utility Model Registration] An air supply chamber connected to a pressurized air source, an output chamber connected to a brake cylinder, an exhaust chamber open to the atmosphere, and an air supply that communicates the air supply chamber with the output chamber. A valve seat protruding around the air supply chamber side of the air hole, an air supply valve biased by a spring so as to be seated on the valve seat, and a tip of the air supply valve facing the air supply hole. A hollow exhaust valve rod that is loosely fitted and has one end open at its tip and the other end open into the exhaust chamber, and a constant pressure air reservoir connected to the brake pipe via a check valve whose direction is opposite to that of the brake pipe. a control piston that receives pressurized air on one side, receives pressurized air from a brake pipe on the other side, and receives a command force to move the exhaust valve rod toward the intake valve based on the amount of pressure reduction in the brake pipe;
A three-pressure control valve for a railway vehicle, which is equipped with a balancing 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 corresponding to the amount of pressure reduction in the brake pipe. , A third method for a railway vehicle, characterized in that 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. Pressure control valve.