AUTOMATIC DRAINING DEVICE FOR AIR-OPERATED SYSTEMS

Abstract: Automatic draining device for air-operated systems, especially of vehicle air brakes. The device can be mounted to a reservoir of the air system and comprises a condensa­ tion chamber (2) and a drain valve (32, 35) which is actuated by a valve-actuator body (3), the actuator body being controlled by means of a servo-valve able to connect the working chamber of the drain valve actuator to a point in the air-operated system which is kept under pressure during its operation; the servo-valve control means being connected to a remote control device for activating said valve at predeter­ mined moments. So, the draining can be effected at a distance from the brake system independently of the braking rhythm and brake pressure.

Description: Automatic draining device for air-opercted systems. The present invention relctes to an automatic draining device for air-opercted systems, especially of vehicle air brakes, orprising a condensation chamber communiccting with the system via a calibrated cpening, and a condenscte-discharge chamber cotrmunicating with a discharge conduit thereof, c valve member Weeing disposed between both chambers which is normally closed when inactive and which is connected to means for opening some at intervals as determined cs a function of pressure variation in the system. In said draining device, the valve is formed with a cylinder in the body of the draining device, in conjunction with a piston adapted thereto and which, via a small separating space, ccn connect said chamber to the discharge conduit means, said piston being joined to another piston having a larger diameter and receiving the broke pressure. The object of the invention is to broaden the range of applica- tion of these types of drain valves by providing an arrangement which is such that it is not necessary to use the brake pressure Fr actuating the condenscte-d scharge valve, while said value can be actuated from any other plcce, even at a distance from the brake system cnd at moments not dependent upon the brcking rythm. To this end, according to the invention, the control pressure for actuating the drain valve is controlled, independent of the bfake-appicction pressure, by means of a valve the passage of which is disposed in o conduit which interconnects the working chamber of the drain-valve actuator and a point in the air-operated system which is kept under pressure during its operation, the servo-valve control means being connected to a remote control device for cctivating said valve at predetermined moments. This eliminctes the possibility of an insufficient rate of draining occurring but instead provides the possibility of being able to effect manual draining at any moment desired by the driver. Putting this main feature of the invention into practice is greatly fccilitated if the servo-valve is formed by a solenoid valve the actuation of which can be effected by any conventional means desired. In this case it is quite convenient to incorporate the solenoid valve into the mounting block of the drain so that its inlet means communicates with the pressure inlet means of the mounting block, its outlet means being connected, via an external pipe, with the inlet means of the drain-valve actuator. This results in a subsequent simplification of the assembly if the servo-valve inlet means extends into a pipe which extends beyond the connection of the draining device in the bottom of the draining reservoir nd lecds to a height not attainable by the condensate cccurulated therein The remote switching device may be any electric switching device controlled by an operating function which is dependent upont the operation of the brake system, and may include, in parallel relation, a hand-operated switch for drain-valve actuation as desired. The accompanying drawings show, by way of example not limitative to the scope of the invention and in schematic representation, a preferred embodiment. In the drawings, Figure 1 is an axial sectional view of a drain vave according to the present inVention taken on line I-I of Figure 2 which shows a top view of the same valve; and Figure 2 is another sectional view of the same valve taken on the line II-II of the said Figure ?. In the figures, the mounting block, the filter-condensation chamber and the valve-actuator body cre respectively indicated by the general reference numerals 1, 2 and 3. At its upper end, the mounting block 1 is provided with an a;iulpr head 4 adapted for fitting the device into the drain hole of one of the reservoirs of the brake system, while, at the other end, it is secured to the upper half 6 of the condensation chamber 2 by means of bolts 5. Said block is provided, on the cne hand, with an axial conduit means 7 which corrunicotes, directly with the inside of the reservoir in which the device is rounted, and with the interior of the condensation chamber, and, on the other hand, with a connection means 8 into which is screwed the body of a solenoid valve 9 whose operating coil 10 is energized at tie appropriate moments through flexible conductors entering the device via a cable connector 11. The valve closing member 12, which is loaded by means of a compression spring 13, abuts against a valve seat 14 formed ot the rear end of the connection means, thus forming the chamber 15 of said valve. The inlet means of saiJ valve is formed by a bore 16, communiccting with the centrcl opening of the seat 14 and extending to the end of the head 4; said bore has secured thereto, in a press-fit or welded relation, a small pipe 17 which is thus 'ousted within the reservoir. In order to ensure that condensate cccunulated within the reservoir cannot reach the pipe opening, this pipe extends above a suitable level and has its end kent as seen at 18. The outlet means of the passage of the solenoid valve herein described is formed by its own valve chamber 15 from which extends a pipe 19 ending in an external connection means 20. The two halves 6 and 21 of the-;condensation chamber 2, which s are joined together by means of bolts 22, retain therebetween a diaphragm filter 23, and the under half 21 carries the body of the valve-actuator 3 secured thereto by means of bolts 24. The body 3 forms a short cylinder 5 which is closed off ty means of a cover 26 and in which cylinder slides a piston 27 which is sealed in an airtight relotion due to a sealing member 28, the piston being urged upwards by a helical spring 29. The head of the cylinder is traversed by a profiled axial boring which communicates with the chamber 2 and comprises, from bottom to top, a guide portion containing a sealing member 30 for a rod 31 projecting from the piston in axial direction and ending in a valve closing member 32; a widened area 33 which forms the chamber for discharging condensate and to this effect communicates with the outside by way of a discharge conduit 34; a bore 35 which forms the valve seat for the closing member 32 and a narrow, calibrated passage 36 allowing the condensate to leave the chamber 2. As seen in the drawings, the working chamber 37 of the cylinder 25 communicates, via c passage 38, with connection means 29, and a pipe 4Q, provided with connections 41, connects said connection means with the outlet connection means 20 of the servovalve. Finally, the piston 27 is traversed by a bore which has a calibrated opening 42 formed therein, on either side of said opening filters 43 being crrcnged which automatically bring about the compensation of pressures and ensure the closing of the drain valve, even if the solenoid-valve control means should remain energized. In operation, when the solenoid-valve is actuated thus opening the seat 14, the compressed air of the reservoir in which the device is mounted, passes via the pipe 17, sect 14, chamber 15, conduit 19 and connection 8, to the external pipe 40 which leads it to the connection 29, from which it passes via the passage 38 to the working chamber 33 in order to move the piston to the discharge position as shown in figures 1 and 2. The rest of the operation is self-evident. Obviously, the solenoid-vlave 9 can be controlled, through appropriate conductors, from an electric switching device located at any convenient place. Without dismissing the possibility of carrying out this operation from a hcnd-operated contact means connected to the brake-operating circuits, said switching device may be loccted at any other place in the brake system, for example at the outlet opening of the compressor, or may be replaced by cn electric device opercted from the electrical installation of the vehicle cs a function of some suitable signcl related to operation thereof. In any case, it is convenient to install a switch in parallel relation to said switching device to allow the manual operation of the draining device.

Claims: Clcinis: 1. An automatic draining device for air-operated systems, especially of vehicle air brakes, characterized in that the control pressure for actuating the drain valve is controlled, independent of the brake-application pressure, by means of a servo-valve, preferably an electromagnetically operated valve, the passage of which is disposed in a conduit which interconnects the working chamber of the drain-valve actuator to a point in the air-operated system which is kept under pressure during its operation, the servo-valve control means being connected to a remote control device for activating said valve at predetermined moments. 2. An automatic draining device for air-operated systems according to claim 1, characterized in that the servovalve is a solenoid valve4 3. An, automatic draining device for air-operated systems according to claims 1 and 2, characterized in that the solenoid valve is incorporated in the mounting block of the drain valve, the inlet means of the servo-valve communicates with the pressure inlet means of the mounting block, and the outlet means of the servo-valve is connected, via an external pipe, with the inlet means of the drain-volve actuator whose actuating piston is traversed by a calibrated opening protected on both side by respective filters. 4. An automatic draining device for air-operated systems according to claims 1 and 3, characterized in that the servo-valve inlet means extends into a pipe which extends beyond the connection of the draining device in the bottom of the draining reservoir and leads to a level not attainable by the condensate accumulated therein. 5. An automatic draining device for air-operated systems according to claims 1 and 2, characterized in that the remote control device is a switching device controlled by an operating function which is dependent upon the operation of the brake system. 6. An automatic draining device for air-operated systems according to claims 1, 2 and 5, characterized in that the switching device includes, in parallel relation, -a-handoperated switch for drain-valve actuation as desired.

Inventors: LOPEZ LINAN, ANTONIO
Applicants: VALVULAS LAC S.A.
Application year: 1984
Main classification: B60T17
IPC codes: B60T17