JPH0534466Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a brake cylinder pressure reducing device for an automatic braking device for a railway vehicle.

[Conventional technology]

A conventional device of this type is shown in FIG. This conventional automatic brake cylinder pressure reduction device has a brake pipe BP that is passed through the train and is pressurized and depressurized by a brake valve (not shown), and a brake pipe that branches off from this brake pipe BP and responds to the pressure increase and decrease of the brake pipe BP. A dual-pressure control valve CV, an auxiliary air reservoir AR that accumulates pressure air that is the source of brake force, and this auxiliary air reservoir
The pressure air accumulated in the AR is transferred to the two-pressure control valve CV
It consists of a brake cylinder BC that generates braking force by supplying air through the brake cylinder BC.

In such a conventional example, if the brake valve (not shown) is operated, the brake pipe
Since BP is pressurized to a predetermined pressure (usually 5 kg/cm ² ), this pressurized air is sent to the auxiliary air reservoir AR via the two-pressure control valve CV and is stored therein. In this state, the brake cylinder BC is communicated with the atmosphere through the two-pressure control valve CV, and no braking force is applied.

In the above operating state, when the brake valve is operated for braking, the brake pipe BP is depressurized according to the amount of operation (common brake band). Then, the two-pressure control valve CV operates in response to this, and the pressure air accumulated in the auxiliary air reservoir AR is sent to the brake cylinder BC.The pressure of the pressurized air in the auxiliary air reservoir AR is the same as the pressure in the brake pipe BP. Supply air until the brake force reaches the desired amount to obtain a braking force commensurate with the amount of operation (see Figure 4).

Normally, the size of the auxiliary air reservoir AR in the above device is designed for each vehicle to match the required brake cylinder BC pressure. However, in a vehicle designed in this way, for example, when changing the material of the brake shoes from cast iron to synthetic resin,
Since the frictional resistance increases, it is necessary to reduce the pressure in the brake cylinder BC by about half.
In this case, replacing the auxiliary air reservoir AR with one with a smaller capacity will increase the repair cost, so normally a new pressure reducing valve FV is installed between the two-pressure control valve BC, as shown in Figure 6. In addition, a limit is placed on the amount of pressurized air sent to brake cylinder BC.

[Problem that the invention attempts to solve]

However, according to the brake cylinder pressure reducing device of the automatic brake system shown in Fig. 6, when the brake valve is operated, air is supplied from the auxiliary air reservoir AR to the brake cylinder BC via the two-pressure control valve CV. When the pressure air is low, it passes through the pressure reducing valve FV and flows into the brake cylinder BC. However, when the pressure air pressure becomes high and exceeds the set pressure of the pressure reducing valve FV, the pressure reducing valve FV closes and the brake cylinder BC is closed. Flow into cylinder BC stops. Then, the pressurized air that is supposed to be sent from the auxiliary air reservoir AR to the brake cylinder BC flows only between the two-pressure control valve CV and the pressure reducing valve FV, so the pressure in this period increases rapidly and the auxiliary air reservoir The pressure is the same as that of the air reservoir AR. As a result, a phenomenon occurs in which air cannot be supplied from the auxiliary air reservoir AR to the brake cylinder BC even if the brake pipe BP is depressurized by the brake operation. In other words, even if the pressure in the brake pipe BP is slightly reduced, the auxiliary air reservoir AR will release the brake cylinder from the auxiliary air reservoir AR.
There is a problem that air supply to the BC ends, resulting in poor controllability, and a problem that mixed operation with other general vehicles that do not have a pressure reducing valve FV is at risk.

This problem can be expressed in concrete numerical terms as follows.

When the brake valve is operated, the brake pipe BP is pressurized to a predetermined pressure of 5Kg/ ^cm2 , and at this pressurized pressure of 5Kg/ ^cm2 , auxiliary air with a capacity VAR of 40 is released. Pressure air is accumulated in the reservoir AR, and the set pressure of the pressure reducing valve FV is set to 1.8 kg/cm ² . When the pressure in the brake pipe BP is reduced by operating the brake valve in this state, 5 kg/cm ² of pressurized air from the auxiliary air reservoir AR is transferred to the pressure reducing valve FV via the two-pressure control valve CV.
Air passes through the air and is sent to the brake cylinder BC, but the pressure in the brake cylinder BC is set at 1.8 kg
When the pressure reaches ^cm2 , the pressure reducing valve FV closes. The capacity of brake cylinder BC, VBC, is 10, and its pressure is
PBC, the pressure of the auxiliary air reservoir AR when braking is applied.
Assuming PAR, the following formula holds true.

Before brake application: VAR × (5Kg/cm ² +1Kg/cm ² ) After brake application: VAR × (PARKg/cm ² +1Kg/
cm ² ) + VBC (PBCKg/cm ² +1 Kg/cm ² ) VAR=40, VBC=10, PBC=1.8Kg/cm ²
By substituting , and connecting the two equations with an equal sign, we get PAR=4.3Kg/cm ² .

In other words, auxiliary air reservoir AR and brake pipe BP
When the pressure reaches 4.3Kg/cm ² , the air supply to the brake cylinder BC is stopped, so the control range is 5Kg/cm ² to 4.3Kg/cm ² , which is the control range of a general automatic brake. (Constant brake band) 5Kg/cm ²
Controllability is inferior to ~3.6Kg/ ^cm2 , and there is a risk of mixed operation with other general vehicles that do not have a pressure reducing valve FV (see Figure 4).

[Means for solving problems]

This idea was devised in view of the above circumstances, and consists of a brake pipe that is passed through the train and is pressurized and depressurized by the brake operation of the brake valve, and a brake pipe that branches off from this brake pipe. A two-pressure control valve that responds to the increase and decrease of pressure in the brake tube, and pressurized air from the brake pipe is supplied through the two-pressure control valve to accumulate pressure air, which is the source of braking force. an auxiliary air reservoir; a brake cylinder that generates braking force by receiving air from the auxiliary air reservoir via the two-pressure control valve; and a pressure reduction provided between the brake cylinder and the two-pressure control valve. In a brake cylinder pressure reducing device for an automatic brake system comprising a valve, a volumetric air reservoir is provided between the two-pressure control valve and the brake cylinder.

[Effect]

According to the above means, since the pressurized air of the auxiliary air reservoir is supplied to the volumetric air reservoir provided between the other two-pressure control valve of the brake cylinder and the brake cylinder via the two-pressure control valve, The amount of pressure reduction in the brake pipe increases until the pressure in the brake cylinder reaches the set pressure of the pressure reducing valve, improving controllability.

〔Example〕

An embodiment of this invention will be described based on FIGS. 1 and 2.

Note that constituent elements common to those of the conventional example shown in FIG. 6 described above are given the same reference numerals, and their explanations will be omitted.

First, a first embodiment of this invention will be described based on FIG.

This first embodiment differs from the conventional example shown in FIG. 6 in that a volumetric air reservoir VR is provided between the pressure reducing valve FV on the brake cylinder BC side of the two-pressure control valve CV and the brake cylinder BC. .

According to this first embodiment, when the brake valve (not shown) is operated, the volumetric air reservoir is
VR is also the same as the conventional example shown in FIGS. 5 and 6, except that it is communicated with the atmosphere through a two-pressure control valve CV, so a description thereof will be omitted.

Next, in the above operating state, when the brake valve is operated for braking, the brake pipe BP is depressurized according to the amount of the operation. Then, the two-pressure control valve CV operates in response to this, and the pressure air accumulated in the auxiliary air reservoir AR flows into the volumetric air reservoir VR and the brake cylinder BC through the pressure reducing valve FV.
When the pressure air exceeds the set value of the pressure reducing valve FV, the pressure reducing valve FV closes and the flow into the volumetric air reservoir VR and the brake cylinder BC is stopped. However, unlike the conventional example, the volumetric air reservoir VR is a two-pressure type control valve.
In order to store the pressurized air in the auxiliary air reservoir AR via CV, the pressure in the brake pipe BP does not reach the set value of the pressure reducing valve FV until it is considerably reduced, so the control range of the automatic brake pipe is expanded to the normal brake band. Therefore, a brake cylinder pressure reducing device with good controllability can be obtained (see FIG. 4).

The second embodiment of this invention shown in FIG. 2 differs from the first embodiment in that a volumetric air reservoir VR is provided between the two-pressure control valve CV and the pressure reducing valve FV. This second embodiment also has the same effects as the first embodiment. More specifically, the volumetric air reservoir VR of the first embodiment stores the pressure air reduced by the pressure reducing valve FV, whereas the volumetric air reservoir VR of the second embodiment is supplied with air from the auxiliary air reservoir AR. This means that the compressed air is directly stored. Therefore,
When trying to accumulate the same volume of pressurized air in the auxiliary air reservoir AR in the volumetric air reservoirs VR of the first and second embodiments, the volumetric air reservoir VR of the second embodiment accumulates high pressure air. Therefore, the volumetric air reservoir VR of the first embodiment can be made smaller.

[Effect of idea]

As is clear from the above explanation, according to this invention, a volumetric air reservoir is interposed between the two-pressure type control valve and the brake cylinder, so that the pressurized air in the auxiliary air reservoir is transferred from the two-pressure type control valve to the brake cylinder. As a result of being able to store the pressure air on the side, it is possible to increase the amount by which the pressure in the brake pipe is reduced until the pressure of the pressure air in the brake cylinder reaches the set pressure of the pressure reducing valve. Therefore, it is possible to obtain a brake cylinder pressure reducing device that can obtain a gentle braking action and has excellent controllability.

[Other means to solve the problem]

Incidentally, as another means for solving the above-mentioned problems, the applicant of the present application proposed the Utility Application 1986-
It is possible to adopt the load/air brake system of No. 7747. That is, as shown in Fig. 3, in addition to the conventional circuit shown in Fig. 5, there is a two-position circuit that communicates the volumetric air reservoir VR with the brake cylinder BC when the vehicle is empty, and blocks this communication when the vehicle is loaded. A volumetric air switching valve ELV with a volumetric air reservoir VR and a safety valve on the volumetric air reservoir VR
The present invention utilizes the circuit when the vehicle is empty in the load-air brake system, which is characterized by providing a safety valve SV and setting the set pressure of the safety valve SV to the normal full brake pressure when the vehicle is empty or slightly higher than that. However, in this case, if the safety valve SV blows air during emergency braking,
Since there is inevitably a pressure difference between the start and end of the safety valve SV, there is a disadvantage that, across the necessary set pressure, the brake cylinder pressure is high at the start and low after it stops. In the case of this invention, since the pressure reducing valve FV is used to limit the pressure to a necessary set pressure, there is an advantage that the pressure value is stabilized.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the first embodiment of this invention;
The figure is an explanatory diagram of the second embodiment of this invention, Figure 3 is an explanatory diagram of another means for solving the problem, and Figure 4 is the relationship between brake cylinder pressure and brake pipe pressure in the conventional example and the present invention. 5 and 6 are explanatory diagrams of the conventional example, respectively. BP...brake pipe, CV...two-pressure control valve,
AR...Auxiliary air reservoir, BC...Brake cylinder,
FV...pressure reducing valve, VR...volume air reservoir.

Claims (1)

[Claim for Utility Model Registration] A brake pipe that is passed through a train and whose pressure is increased or decreased by operating the brake valve, and a two-pressure control valve that branches off from this brake pipe and responds to the pressure increase or decrease in the brake pipe. , an auxiliary air reservoir that accumulates pressure air that becomes a source of brake force by supplying pressurized air from the brake pipe via the two-pressure control valve, and a two-pressure control from the auxiliary air reservoir. In a brake cylinder pressure reducing device for an automatic braking device, which includes a brake cylinder that generates braking force by being supplied with air via a valve, and a pressure reducing valve provided between the brake cylinder and the two-pressure control valve. A brake cylinder pressure reducing device for an automatic brake system, characterized in that a volumetric air reservoir is provided between the two-pressure control valve and the brake cylinder.