EA019526B1 - Pneumatic control valve with regulated compressed air feed to a brake cylinder - Google Patents

Abstract

Pneumatic control valve for feeding compressed air in a regulated way to a brake cylinder which can be connected via a compressed air connection (C), having at least one integrated seat valve arrangement (4, 5) for ventilating or venting the brake cylinder in accordance with the pressure in a main air line which can be connected by means of a compressed air connection (L), wherein additional valve means are integrated for the controlled re-charging of a reservoir air container, which can be connected via a compressed air connection (R), during the venting time of the brake cylinder, wherein the additional valve means in order to ensure throttled re-charging of the reservoir air container over at least part of the venting time of the brake cylinder comprise a choke valve (10) which has a spring reset and is inserted into a valve-internal "R" duct (11) which starts from the compressed air connection (R), has a piston (12) which extends in actuating the throttle valve against the force of a restoring spring (13) and also has minimum and maximum throttle cross-sections through a piston (12) coaxially formed throttle pin (14) is generated in dependence on the piston position, in cooperation with the throttle pin (14) surrounding the stationary passage bore (15), wherein circular segment-like recess (17) realizes the maximum throttle cross section in the retracted basic position of the throttle pin (14), the circular outer cross-section of the restrictor pin (14) realizes the minimum throttle cross-section in the extended operating position in actuating the throttle valve.

Description

The present invention relates to an air distributor for controlled supply of compressed air to a brake cylinder connected via pneumatic connection C, while the air distributor has at least one built-in valve system with a valve for supplying air to the brake cylinder or removing air from the brake cylinder depending on pressure pneumatically connected to the main air line b, with additional valve means for controlled refilling connected by pneumatic connection to the spare air tank during the removal of air from the brake cylinder.

The scope of application of the present invention extends to the construction of a rail vehicle. In this case, within the framework of pneumatic brake systems, pneumatic air distributors of interest in this case are used as a regulating element for supplying air to the brake cylinder. At the same time, the regulating element also controls the filling of the auxiliary air tank or the reserve air tank and, depending on the pressure in the main air line Hb of the rail vehicle, in its main function creates the corresponding brake cylinder pressure or indirect control pressure. At the same time, the air distributor forms the central braking control for each one mediated by an active, automatic single-chamber pneumatic brake, depending on the pressure change passing through the main air line b directly or as an indirect control pressure for the connected main part to control the air supply to the connected brake cylinder or removing air from the connected brake cylinder.

The basic design and principle of operation of the air distributor with stepped release is of interest from the Reference book of the Basics of brake technology (ΚΝΟΚΚ-ΒΚΕΜ8Ε OMVN, 2nd ed., 2003, p. 118 and further). The pneumatic air distributor is made monolithically and flanged to the air distributor support, by means of which the necessary pneumatic connections with the main air line, the spare air tank and the brake cylinder are installed.

Inside the air distributor there is a control piston, which is supplied with compressed air from both sides and which is the main component of the piston group, creating various pressure forces in the main air line b, pressure in the brake cylinder C and pressure in the control chamber A using various acting surfaces , in order to actuate a double-seat valve system to supply air to a connected brake cylinder or to bleed air from a connected brake center Lindrum.

With the help of a pneumatic distributor, the pneumatic brake when filled with compressed air through the main air line HB is brought to the charging (operating) pressure. Filling is complete when the pressures b, k and a are equal. When braking, the pressure in the main air line Hb decreases. By changing the pressure parameters on the piston group, it is set in motion as soon as the force of the built-in compression spring is overcome. As a result, the stepped release air diffuser is in the deceleration position. At the same time, the first connection on the double valve is first closed to remove air from the pneumatic connection C of the brake cylinder and then the second connection is opened. The compressed air of the spare air tank flows through it, which is connected to the brake cylinder through pneumatic connection K, through pneumatic connection C, due to which the pressure of the brake cylinder in the brake cylinder increases.

To release the air brake, the pressure in the main air line Hb increases. As a result of this, the piston group moves in order to occupy the brake release position. Due to this, there is a connection with the air exhaust of the pneumatic connection C of the brake cylinder with a connection for the removal of air that goes into the atmosphere. The brake cylinder pressure is reduced until the closing position is engaged. At the same time, however, the compressed air of the main air line Hb flows through the built-in non-return valve in the direction of the pneumatic connection L of the main air line to the spare air tank in order to refill it. As a result, the pneumatic diffuser is ready for re-braking.

Compressed air consumption, due to the refilling of the reserve air tank, slows down, first of all, with long trains, filling the main air line Hb at the rear of the train. This leads to a slower release time of the air brake and a slower filling of the spare air tank at the rear of the train. Particularly clearly felt is the consumption of compressed air by the reserve air tank when the filling jerk (tempering jolt), that is, with the pulsed supply of compressed air. In this case, the spare air tanks in the front of the train are partially overloaded, and the filling impulse after several waves completely subsides.

In order to avoid the above-mentioned problems, solutions are known from the general prior art that suppress filling jolts due to the controlled refilling of the spare air reserve.

- 1 019526 voara through additional valve means. The basic principle of such a controlled refill is that it is performed after a certain phase of release of the air brake, that is, during the removal of air from the brake cylinder through a reduced flow section. Due to this, refilling significantly slows down and less compressed air enters the spare air tank, as a result of which more compressed air is available to fill the main Hb air line at the rear of the train. However, on the other hand, spare air tanks must be filled with compressed air, at least so that sufficient compressed air is available for subsequent braking. Due to such controlled refilling of spare air tanks, filling jolts are prevented or they only partially enter spare air tanks.

The additional valve means still used for this are of relatively complex construction and consist of many separate parts. Typically, additional valve means are subject to several pressures, such as indirect pressure control of the brake cylinder, stored pressure, and pressure in the main air line.

Therefore, the objective of this invention is to equip the air distributor for controlled supply of compressed air into the brake cylinder with additional valve means of simple construction for controlled refilling of a connected spare air tank, which can be compactly integrated into a pneumatic air distributor.

Based on the air distributor according to the restrictive part of claim 1 of the claims, this problem is solved in combination with its distinctive features. Subsequent dependent clauses reflect preferred improvements of the invention.

The invention includes the technical solution consisting in that additional valve means for the throttled refilling of a spare air tank during at least a part of the time for removing air from the brake cylinder include a throttle valve which is inserted into a pneumatic connection K, which is made inside the air distributor channel K and which has a piston built into it, displaced when the throttle valve is triggered against the force of the return spring, as well as the minimum and maximum flow sections are created depending on the position of the piston by means of a throttle neck coaxially formed on the piston in conjunction with the stationary through hole of the throttle neck that is fixed, the maximum flow cross section of the throttle valve is realized by a groove in the throttle neck in the initial piston position and the minimum flow area of the throttle valve realizes the circular outer cross section of the throttle neck in an offset th position of the piston during actuation of the throttle valve.

The advantage of the proposed solution lies primarily in the fact that such a spring-return throttle valve, constructed from a small number of parts, can be compactly integrated into the K channel area of the air distributor.

Many pneumatic air distributors in the area of pneumatic connection K for the spare air tank have a bolt screw that can be simply replaced with the proposed spring return throttle valve in order to expand the pneumatic air distributor with the function of controlled refilling of the spare air tank. Due to this technically simple solution, it is possible to optimize the flow of compressed air when the pneumatic brake is released with respect to the release time and the pressure build-up in the main air line Hb. At the same time, the proposed spring return throttle valve reduces the compressed air consumption of spare air tanks filled when the brake is released from the main air line Hb to the most necessary, due to which the criterion of infinite availability of compressed air is only satisfied. Using the proposed solution, although it is not possible to throttle the refilling of the spare air tank during the entire release time, however, sufficient filling of the spare air tanks is achieved due to the throttled supply of compressed air and unwanted filling jerks can be prevented to a sufficient degree.

The principle of operation of the throttle valve with spring return is based on the change in the flow area for inflowing through the main air line Hb to the spare air tank of compressed air. Due to the action of the return spring, the piston at low pressure values is in the initial position and provides, at the same time, the maximum flow area of the throttle valve. With increasing pressure, the piston moves to the throttle valve's trigger position, in which the throttle valve flow area is minimal.

As mentioned above, to implement this function, it is proposed to perform a coaxial throttle neck directly on the piston, which, depending on the position of the piston, creates different flow sections of the throttle valve with the fixed inlet through it.

According to simply implemented from the point of view of manufacturing techniques, improvements to this

- 2,019,526 constructive solutions maximum throttle valve flow area is created by a notch made in the form of a circular segment in the middle section of the choke neck, which can be done, for example, in the form of a milling notch or the like On the contrary, the minimum flow area of the throttle valve can be created due to a circular external cross section of the throttle neck, which, with the throughput hole surrounding it, forms an annular gap that has a smaller flow area than the flow section created in the area made in the circular groove segment in throttle neck.

When selecting the sizes of the minimum and maximum throttle valve flow areas, it should be noted that the refill of the reserve air tank is selected so that the brake pressure during the subsequent braking can still reach the prescribed pressure value.

In the preferred embodiment of the proposed pneumatic air distributor, it has a detachable (prefabricated) structure, including a main part for creating brake pressure and a main part for indirect (preliminary) control, which are flanged to a common air distributor support part with built-in pneumatic connections K, C, b.

It is preferable that the main part has an integrated control piston, on which, on the one hand, through the first control chamber, pressure of the main air line b is supplied, and on the opposite side, through the second control chamber, the reference pressure, to create by means of a piston rod with a first valve system indirect pressure control seat for the main part. The main part has the function of a relay valve and, when fed through the built-in second valve system with a seat valve, the stored pressure supplies brake pressure. Along with this, both in the trunk part and in the main part, other additional functions characteristic of air brakes are also integrated.

A particular advantage is that the proposed throttle valve for controlled refilling of the spare air tank is made in the form of a cartridge threaded valve. In this case, the throttle valve can be screwed in place of one of the pneumatic distributors of the bolt screws normally located in the case of interest in this case into the main body casing. This makes it particularly easy to retrofit the indirect-control pneumatic valve with the proposed controlled refill function.

Other measures that improve the invention are described below, together with a description of the proposed embodiment on the example of the drawings:

FIG. 1 is a partial image of a longitudinal section of a combined pneumatic air distributor with a main part and a main part;

FIG. 2 is a longitudinal section of a throttle valve with a spring return in the form of a cartridge threaded valve; and FIG. 3 is a graphic representation of the temporal characteristic of refilling the spare air tank with compressed air.

According to FIG. 1, a pneumatic air distributor for a regulated supply of compressed air to a brake cylinder of a pneumatic brake system for a rail vehicle not shown in more detail has a modular structure and basically consists of the main part 1 and the main part 2, while both are flanged to the middle supporting part of the air distributor. Basically, the main part 1 serves to create the brake pressure and performs this switching function by means of the valve system with a saddle gate built in here. The creation of brake pressure is powered by a pneumatic connection K, which establishes a connection with a spare air tank. On the contrary, the brake cylinder is located on the pneumatic connection C on the support part 3 of the air distributor. The main part 1 is actuated by means of pneumatic indirect control, which is activated by the main part 2 by means of the valve device 5 integrated here. The valve system 5 with the valve seat is actuated by means of the control piston 6, which is supplied to one side via the first control chamber 7 air line, which is supplied from the main air line Hb not shown through pneumatic connection L of support 3 of the air distributor. On the opposite side to the control piston 6 through the second control chamber 8 is supplied reference pressure.

A bolt screw 9 is screwed into the body of the main part 1, which closes the K 11 channel inside the distributor relative to the atmosphere.

The above-mentioned bolt screw 9 can be replaced as shown in FIG. 2 spring-loaded butterfly valve 10 with spring return. The throttle valve 10 is made in the form of a cartridge screw valve and can thus be simply installed instead of the locking screw 9, i.e. screwed into the channel K 11 of the hull of the main part. Spring return throttle valve 10 serves as an additional valve means for the controlled refill of the spare air tank during the removal of air from the brake cylinder, i.e. during the release of the air brake 3,012,652.

For this purpose, an axially displaceable piston 12 is built into the spring-return throttle valve 10, which can be powered by compressed air moving in the direction of the spare air tank, overcoming the force of the return spring 13. In this situation, the piston 12 provides the maximum flow area of the throttle valve, while when the throttle valve is triggered due to the displacement of the piston 12, the minimum flow area of the throttle valve is set. The minimum and maximum flow sections are formed depending on the position of the piston by means of a throttle neck 14 coaxially mounted on the piston 12 in cooperation with the surrounding throttle neck 14 with a fixed through hole 15. At that, the fixed through hole 15 is made from the bottom in the threaded housing 16 of the air distributor. For maximum flow area of the throttle valve, the throttle neck 14 is made in the form of a circular segment of the notch 17. The minimum flow area of the throttle valve, on the contrary, is formed by the interaction of a circular outer cross section at the end of the throttle neck 14 and is formed by leaving a small annular gap between the throttle neck 14 and the surrounding orifice 15.

In this exemplary embodiment, the refill feature for the spare air tank may vary due to an adjusting screw 19 screwed into the screw cap 18. The adjusting screw 19 of the throttle valve 10 acts on the opposite side of the return spring 13 opposite to the piston 12 to compress it. Due to this, the pressure value increases, starting from which a stronger throttling of the throttle valve 10 with spring return starts. Thus, by means of the adjusting screw 19, the return force applied by the return spring 3 to the piston 12 is varied.

FIG. Figure 3 shows the pressure change characteristic for refilling the reserve air tank along time axis 1. Starting with a 4.5 bar pressure on the defining characteristic curve I, throttling begins. Starting from this event, further refilling of the reserve air tank is performed more slowly to a maximum value of 5.5 bar. If the normal charging pressure is higher, then the maximum value is also correspondingly higher. In this case, the switching value for throttling can be selected depending on the requirements.

The characteristic curve II schematically shows the characteristic of the corresponding effective valve flow area. Rapid filling occurs with an effective cross section of approximately 1.3 mm, and a choked filling with a passage section of approximately 0.7 mm.

The invention is not limited to the preferred embodiment described above. Moreover, variations are also possible, which are also covered by the protection scope of the following claims. For example, it is also possible that the proposed spring return throttle valve 10 for adjustable refilling of a spare air tank in a pneumatic braking system known from the prior art may not be in the form of a cartridge valve, but in the form of a flanged valve, or be embedded in the housing monolithic air distributor.

List of reference designations.

- Main part,

- main part,

- supporting part of the air distributor,

- the second valve device,

- the first valve device,

- control piston

- the first control camera,

- the second control chamber,

- bolt screw,

- throttle valve,

- channel B,

- piston

- return spring

- throttle neck,

- throughput hole

- threaded body,

- notch,

- screw cap,

- adjusting screw

C - pneumatic connection for the brake cylinder,

B - pneumatic connection for the main air line,

- 4 019526

K - pneumatic connection for a spare air tank.

Claims (6)

CLAIM 1. Pneumatic air distributor for adjustable compressed air supply to the brake cylinder connected via pneumatic connection (C), while the air distributor has at least one built-in valve system (4, 5) with a seat valve for supplying air to the brake cylinder or removing air from the brake cylinder depending on the pressure of the main air line connected by pneumatic connection (B), with additional valve means built in for controlled About refilling of a spare air tank connected via pneumatic connection (K) during air removal from the brake cylinder, characterized in that additional valve means for throttled refilling of a spare air tank during at least part of the time for air removal from the brake cylinder include a throttle valve (10), which is inserted into the channel K (11) connected to the pneumatic connection (K), which is made inside the air distributor, and which there is a piston (12) built into it, displaced when the throttle valve is actuated against the force of the return spring (13), and also has minimum and maximum flow sections created depending on the position of the piston (12) by means of a throttle neck coaxially formed on the piston (12) (14) in conjunction with the surrounding throttle neck (14) with a fixed inlet opening (15), with the maximum flow area of the throttle valve (10) realizes a notch (17) in the throttle neck (14) in the throttling neck (14) th position of the piston (12), and the minimum flow section of the throttle valve (10) implements a round external cross section of the throttle neck (14) in the displaced position of the piston (12) during actuation of the throttle valve. 2. Pneumatic air distributor according to claim 1, characterized in that it is made in the form of a detachable structure including a main part (1) for creating a braking pressure and a main part (2) for indirect control, which are flanged to a common bearing part (3) of the air distributor with built-in pneumatic connections (K, C, B). 3. Pneumatic air distributor according to claim 2, characterized in that the main part (2) has a built-in control piston (6) on which pressure (B) of the main line is supplied to one side through the first control chamber (7), and on the opposite side through the second control chamber (8) - reference pressure, to create, in cooperation with the first valve system (5) with the seat valve, the indirect control pressure for the main part (1), which, when fed through the built-in second valve system (4) with the seat valve Asennogo pressure (K) provides brake pressure (C). 4. Pneumatic air distributor according to claim 1, characterized in that the throttle valve (10) is made in the form of a cartridge threaded valve screwed into the channel K (11) of the main body (1). 5. Pneumatic diffuser according to claim 1, characterized in that the throttle valve (10) contains an adjusting screw (19), by means of which the return force applied by the return spring (3) to the piston (12) is varied. 6. Pneumatic brake system of a rail vehicle whose brakes are designed to be activated by supplying air to the brake cylinder or by removing air from the brake cylinder controlled by an air distributor in accordance with one of the preceding paragraphs.