JPS6232934Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air leak prevention valve used in an air service brake system of an automobile.

Conventionally, in this type of air service brake system, when the brake pedal attached to the brake valve is depressed, compressed air at a pressure corresponding to the pedal depression is released to the front brake chamber via a quick release valve. The front brake chamber is actuated, and at the same time the compressed air sent by pressing the brake pedal acts on the relay valve, and air with a pressure equal to the pressure of the compressed air is released. The fuel is sent from the tank to the rear brake chamber via the relay valve, and the rear brake chamber is activated.

Therefore, if a failure that causes air leakage occurs on the front brake chamber side or the rear brake chamber side, sufficient compressed air will not be sent to the brake chamber on the side where the failure occurred. Not only that, but the air leakage also affected other brake chambers, and there was a risk that these brake chambers would not be able to obtain sufficient braking force.

In addition, as a countermeasure against such air leaks, we have installed spring brakes, which operate the brakes using the force of a spring, in case the air pressure in the brakes drops due to a malfunction and the air service brakes become ineffective. Some brakes are equipped with a type safety device, but this type of safety device is configured to operate only when the air pressure of the brake drops below a certain level, so even after a failure occurs, the air pressure will continue to decrease. This resulted in the air leak being left unattended until it dropped below a certain level.

The purpose of this invention is that if a failure that causes air leakage occurs on either the left or right side of the front brake chamber side or the rear brake chamber side, the brake chamber on the side where the failure occurred will be replaced. To provide an air leak prevention valve that immediately shuts off the supply of compressed air and hardly affects the normal operation of other brake chambers.

With these issues in mind, the air leak prevention valve of this invention has a valve casing and a valve casing.
A main air chamber is formed in the casing and has an air inlet port connected to the brake valve side on one side and an exhaust port on the other side, and the main air chamber is formed in the valve casing.
A sub air chamber formed separately from the air chamber and having a pair of ports on both sides connected to a pair of brake chamber sides, and its main air chamber.
A communication passage connecting the air chamber and the sub air chamber, and an air inlet port arranged in the main air chamber to open and close in response to compressed air sent from the brake valve side. It has a diaphragm poppet and a plurality of through holes at appropriate positions, and is appropriately spaced from the inner wall surface of the sub air chamber in which the communication passage is opened, and the pair of ports are opened. On the inner wall of the sub air chamber,
a cylindrical shuttle guide fixedly disposed within the sub-air chamber with opposite ends positioned around the pair of ports; and a cylindrical shuttle guide slidably disposed within the shuttle guide and normally The shuttle guide is held in a substantially neutral position to allow compressed air to flow to both of the pair of brake chambers, and when a pressure difference is created between the pair of brake chambers, the reduced pressure is applied to the brake chamber.
It consists of a shuttle that is slid into the shuttle guide toward the port of the sub-air chamber on the chamber side to shut off the port.

Hereinafter, preferred specific examples of the air leak prevention valve according to this invention will be described with reference to the drawings.

FIG. 1 shows ten specific examples of the air leak prevention valve of this invention.

The air leak prevention valve 10 includes a valve casing 11, an air inlet port 20 connected to a brake valve 32 on one side, and an exhaust port 2 on the other side.
1 main air chambers 12 each having 1
and a sub air chamber formed within the valve casing 11 apart from the main air chamber 12 and having a pair of ports 22 and 23 connected to a pair of brake chambers 37 and 38 on both sides. 13, a communication passage 14 that connects the main air chamber 12 and the sub air chamber 13, and an air inlet port 20 that opens and closes in response to compressed air sent from the brake valve 32 side. The diaphragm poppet 15 is disposed within the main air chamber 12, and the sub air chamber 13 has a plurality of through holes 29 at appropriate positions and the communication passage 14 is opened. On the inner wall surface of the sub air chamber 13 that is appropriately away from the wall surface and has the pair of ports 22 and 23 opened, the sub air chamber 13 is placed at both ends around the pair of ports 22 and 23. - Cylindrical shuttle guide 26 fixedly arranged within the air chamber 13
and is slidably disposed within its shuttle guide 26 and normally
is held in a substantially neutral position to allow compressed air to flow through both of the pair of brake chambers 37 and 38, and when a pressure difference occurs between the pair of brake chambers 37 and 38, the depressurized brake・That sub air on the chamber 37 side.
Its sub air chamber 1 on the port 22 or brake chamber 38 side of chamber 13
3 and a shuttle 16 that blocks the ports 23 of 3.

The valve casing 11 has a main air chamber 12 and a sub-air chamber 13 spaced apart below the main air chamber 12 inside, and a main air chamber 12 and a sub-air chamber 13 arranged at a distance below the main air chamber 12. - A valve casing body 17 forming a communication passage 14 communicating with the chamber 13, and the valve casing body 17
The main air chamber side cover 18 is screwed upward, and the sub air chamber side cover 19 is screwed onto the outside of the valve casing body 17 in which the sub air chamber 13 is formed. There is.

That is, the valve casing body 17 forms a vertical cylindrical main air chamber 12 in the upper inner part, and a horizontal cylindrical main air chamber 12 is formed below the main air chamber 12 at a position offset to one side. The main air chamber 12 and the sub air chamber 13 are connected by a communication passage 14, and the bottom of the main air chamber 12 forms a sub air chamber 13. Almost the center of the wall is built up into a truncated conical shape, and a vertical exhaust port 2 is installed in the built up area.
1 is formed, and a port 23 whose inner periphery is threaded is formed in the side wall of the sub-air chamber 13.

In addition, a main air valve screwed into the upper end of the valve casing body 17 formed in this way is also provided.
The chamber-side cover 18 has an air inlet port 20 whose inner periphery is threaded approximately in the center, and a recess 51 in the inner center portion.

Of course, the outer circumference of the upper end of the valve casing body 17 and the inner circumference of the lower end of the main air chamber side cover 18 are threaded so that they can be screwed into each other.

Also, the lower outer side of the valve casing body 17, that is, the sub air chamber 13
The sub-air chamber side cover 19, which is screwed into a position opposite to the port 23, has a port 22 formed approximately in the center thereof, and the inner periphery thereof is threaded.

Of course, the sub air chamber side cover 19
The inner periphery of the valve casing body 17 at the position where the valve casing body 17 is attached and the outer periphery of the tip of the sub air chamber side cover 19 are threaded so that they can be screwed into each other.

Valve casing 11 so configured
A diaphragm poppet 15 is disposed within the main air chamber 12 of the main air chamber 12 to open and close the air inlet port 20 in response to compressed air supplied therethrough.

The diaphragm poppet 15 is composed of a diaphragm portion and a poppet portion integrally extending from the lower surface of the diaphragm portion at approximately the center thereof,
Its main air chamber 1 by means of a spring retainer 24 and a valve spring 25.
It is installed within 2.

That is, the diaphragm portion of the diaphragm poppet 15 opens and closes the air inlet port 20, and the poppet portion opens and closes the exhaust port 21.

Further, within the sub-air chamber 13 of the valve casing 11 configured as described above, the shuttle 16 is guided by the cylindrical shuttle guide 26 and connected to the ports 22, 2.
3 is arranged so that it can be closed.

The shuttle 16 is formed into a substantially cylindrical shape, and has ring-shaped ribs 27, 2 on both end surfaces.
8 protrudes and is manufactured so as to be able to seal the ports 22, 23 by closely contacting the inner wall surface of the sub-air chamber side cover 19 and the valve casing body 17, in which the ports 22, 23 are formed.

The shuttle made with such structure 1
6, of course, when the pressure between the ports 22 and 23 is approximately equal, that is, in a normal state where the brake operation is performed normally, the shuttle guide 2
6 is held at an almost neutral position, and a pressure difference is created between the ports 22 and 23, and an amount of compressed air that far exceeds the amount of compressed air that flows during normal braking operation is transferred to the depressurized side. As the air flows to the port 22 or the port 23 of the air, the air is slid into the shuttle guide 26 and is disposed within the sub-air chamber 13 such that the port 22 or the port 23 can be sealed.

The shuttle guide 26 is formed in a cylindrical shape so as to enable the shuttle 16 to perform the above-mentioned operation, and has a plurality of through holes 29 bored at appropriate positions so that the compressed air can flow through the shuttle guide 26. The water flows from the communication passage 14 to the ports 22 and 23, and from the ports 22 and 23 to the communication passage 14.

In addition, the shuttle guide 26 is
With the air chamber side cover 19 removed, remove the sub air chamber of the valve casing body 17.
It is placed slightly away from the inner wall surface of the chamber 13 and is fixed by screwing the sub air chamber side cover 19 onto the valve casing body 17.

Therefore, when arranging the shuttle guide 26 within the sub air chamber 13,
Port 2 on both sides of the sub-air chamber 13, i.e. the valve casing body 17
A ring-shaped groove 53 is formed around the inner opening of the sub-air chamber side cover 19.
It is desirable to form a similar ring-shaped groove 52 around the inner opening of the port 22 in the
With the sub-air chamber side cover 19 removed, fit one end of the shuttle guide 26 into the groove 53, insert the shuttle 16 into the shuttle guide 26, and then The other end is the sub
The sub air chamber side cover 19 is screwed into the valve casing body 17 so as to be fitted into the groove 52 of the air chamber side cover 19, so that the shuttle guide 26
is fixed within its sub-air chamber 13.

In this way, the shuttle 16 is placed in the sub-air chamber 13, and when the shuttle 16 is fitted in the approximately neutral position, the shuttle
The guide 26 holds the shuttle 16 in its approximately neutral position when the pressures between its ports 22, 23 are approximately equal, thus allowing air to flow from its main air chamber 12 through its communication passage 14 to its sub-air chamber. The compressed air sent into the air chamber 13 is sent equally to both ports 22, 23 through the through hole 29, and is also discharged following the opposite path to that described above.

Furthermore, when a pressure difference occurs between the ports 22 and 23, a large amount of compressed air flows into the port 22 or port 23 on the reduced pressure side, so the shuttle guide 26
6 can no longer be held in its neutral position, and the shuttle 16 is slid toward its port 22 or its port 23 on its depressurized side, Alternatively, the rib 27 or the rib 28 is brought into close contact around the port 23 to seal the port 22 or the port 23 to the shuttle 16.

Next, the air leak prevention valve 10 according to this invention
The operation will be explained with reference to FIGS. 1 and 2.

Figure 2 shows air leak prevention valve 1 according to this invention.
3 shows an air service brake system 30 of an automobile to which the 0 is applied.

The air service brake system 30 includes an air tank 31 and a brake valve 32 connected to the air tank 31 via piping 44.
, an air leak prevention valve 10 connected to the brake valve 32 via a pipe 54, and a pair of front air leak prevention valves connected to ports 22 and 23 of the air leak prevention valve 10 via pipes 47 and 48, respectively. The control port 41 is connected to the piping 5 so that it can be actuated by compressed air delivered from the brake chambers 37, 38 and their brake valves 32.
The inlet port 42 is connected to the air tank 31 through the branch joint 35 inserted into the piping 4.
Relay valve 34 connected via 6, 45
and a branch type joint 3 connected to the outlet port 43 of the relay valve 34 via a pipe 55.
6 and a pair of rear brake chambers 39 and 40 connected to each other via piping 49 and 50, respectively.

That is, the air leak prevention valve 10 is located at the installation position of the quick release valve in a normal air service brake system, and the rear end of the pipe whose tip is connected to the brake valve 32 is connected to the rear end of the pipe. , is connected to the air inlet port 20 of the air leak prevention valve 10, and piping 47, 48 connected to the front brake chambers 37, 38 are connected to the ports 22, 23 of the air leak prevention valve 10, respectively. There is.

Of course, these pipes 54, 47, and 48 are connected via connectors (not shown) with threaded ends.
Air inlet port 2 of the air leak prevention valve 10
0 and ports 22 and 23, respectively.

Therefore, when the brake pedal 33 attached to the brake valve 32 is now depressed, compressed air is sent from the brake valve 32 to the air leak prevention valve 10 via the piping 54, and furthermore, the compressed air is It is sent to the front brake chambers 37, 38 via pipes 47, 48, and the front brake chambers 37, 38 are actuated, and the front wheels (not shown) are braked, and at the same time the brake pedal 33 is depressed. compressed air is sent via line 46 to relay valve 34, which in turn
Compressed air is sent from the air tank 31 through the pipe 45 at almost the same pressure as the compressed air produced by pressing the pedal 33, and the compressed air passes through the relay valve 34 and is sent to the pipe 55 and the pipe 49. , 50 to the rear brake chambers 39, 40, which operate the rear brake chambers 39, 40 to brake the rear wheels (not shown).

That is, the compressed air sent from the air inlet port 20 of the air leak prevention valve 10 is
The periphery of the diaphragm portion of the diaphragm poppet 15 is pushed open against the spring 25, and the compressed air is sent into the main air chamber 12 through the communication passage 14 to the sub-air chamber.
The air is sent into the air chamber 13.

When compressed air is sent into the sub-air chamber 13 in this way, if there is no failure in the front brake chambers 37, 38 or their piping 47, 48 that would cause air leakage, that is, When there is almost no pressure difference between the ports 22 and 23, the shuttle 16 is held in the neutral position within the shuttle guide 26 and the ports 22 and 23 are left open. , compressed air is supplied to both front brake chambers 37,38.

Of course, when the brake pedal 33 is released, the pressure on the air inlet port 20 side, that is, on the supply side, becomes smaller than the pressure in the main air chamber 12 and the sub air chamber 13, and the valve spring 25, the periphery of the diaphragm poppet 15 comes into close contact with the inner circumferential surface of the main air chamber side cover 18, thereby closing the air inlet port 20, and at the same time, the main air chamber 12 and sub air chamber side cover 18 are closed. Chamber 1
Since the pressure in 3 is higher than the pressure on its supply side, the poppet portion of its diaphragm poppet 15 is lifted upwards, and the diaphragm poppet 15 is lifted upward.
The lower end of the poppet 15 separates from the bottom wall forming the exhaust port 21 and opens into its main air chamber 1.
2 and the compressed air in the sub-air chamber 13 are exhausted.

Furthermore, when compressed air is sent into the sub-air chamber 13 as described above, air leakage may occur in either the front brake chambers 37, 38 or their piping 47, 48. If there is a failure, that is, if air leakage causes a pressure difference between ports 22 and 23, the shuttle 16 will
Within the shuttle guide 26, the pressure difference causes the shuttle to be biased toward the port 22 or 23 on the reduced pressure side, and its rib 27 or 28 tightly wraps around the port 22 or 23 on the reduced pressure side. Close that port 22 or 23.

Of course, when the brake pedal 33 is released, either port 22 or 23 is kept closed by the shuttle 16 and the air is exhausted in the same manner as in the above case.

Therefore, the shuttle 16 closes the port 22 or 23 on the side where the air leak is occurring to prevent the air leak and continues the function of the other front brake chamber 37 or 38 on the side where the air leak is not occurring. and maintain it.

The air leak prevention valve 10 described above has been described as being applied to the front brake chambers 37 and 38, but it can also be applied to the rear brake chambers 39 and 40.

Further, in the air leak prevention valve 10 described above, a switch (not shown) that is energized when the shuttle 16 is biased to one side is installed, and the switch is disposed inside the cab (not shown). It is also possible to connect it to an alarm device (not shown) to warn the driver of air leakage.

According to the above-mentioned invention, the cylindrical shuttle guide has a plurality of through holes at appropriate positions, and is appropriately spaced from the inner wall surface of the sub-air chamber in which the communication passages are opened, and On the inner wall surface of the sub-air chamber to which the pair of ports are opened, a shuttle is fixedly disposed within the sub-air chamber with both ends positioned around the pair of ports; is slidably disposed within the shuttle guide and is normally held in a substantially neutral position in the shuttle guide to allow compressed air to flow to both of the pair of brake chambers; When a pressure difference occurs on the brake chamber side of the
It slides into its shaft guide towards the port of the chamber and shuts off that port, so it can be used on either the left or right side of the front brake chamber side or rear brake chamber side of an automobile's air service brake system. If one side has a failure that causes an air leak, a pressure difference will develop between that port, and an amount of compressed air far in excess of the amount of compressed air flowing during normal braking will cause that failure. flow to that port on the side that caused the failure, and that shuttle guide could no longer hold the shuttle in the neutral position, causing the failure.
By sliding the shuttle toward that port on the so-called depressurized side, the shuttle seals the depressurized side port, so that the compressed air supplied to the brake chamber on the failed side is It is immediately shut off, preventing accidents caused by air leakage to a minimum, and ensuring braking operation in the other normal brake chamber without being affected by air leakage, ensuring safe driving of the car. Furthermore, the quick release valve is of integrated construction, so the air service
The number of piping connections in the brake system is reduced, making piping work easier and more practical.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing a specific example of the air leak prevention valve according to this invention, and Fig. 2 is a schematic diagram showing an air service brake system of an automobile to which the air leak prevention valve according to this invention is applied. . 10...Air leak prevention valve, 11...Valve casing, 12...Main air chamber, 13...Sub air chamber, 14...Communication passage, 15...Diaphragm poppet, 16
...Shuttle, 20 ...Air inlet port, 21
...Exhaust port, 22, 23...Port, 32...
...brake valve, 37, 38...brake valve,
Chiyamba.

Claims (1)

[Scope of Claim for Utility Model Registration] A valve casing, and a main valve formed within the valve casing, which has an air inlet port connected to the brake valve side on one side and an exhaust port on the other side.
an air chamber; a sub-air chamber having a pair of ports formed within the valve casing and separate from the main air chamber and connected to a pair of brake chamber sides on each side;・A communication passage connecting the air chamber and the sub-air chamber, and a passage in the main air chamber to open and close the air inlet port in response to compressed air sent from the brake valve side. It has a diaphragm poppet arranged and a plurality of through holes at appropriate positions, the communication passage is appropriately spaced from the inner wall surface of the sub air chamber in which it is opened, and the pair of ports are opened. On the inner wall surface of the sub-air chamber, a cylindrical shuttle guide is fixedly disposed within the sub-air chamber with both ends positioned around the pair of ports; is slidably disposed within the guide and is normally held in a substantially neutral position of the shuttle guide to allow compressed air to flow to both of the pair of brake chambers; When a pressure difference occurs between
and a shuttle slid into the shuttle guide to block the port of the sub-air chamber on the side of the depressurized brake chamber.