GB2133122A

GB2133122A - A flow control valve

Info

Publication number: GB2133122A
Application number: GB08332596A
Authority: GB
Inventors: Hubert Haussler; Peter Suter
Original assignee: BERINGER HYDRAULIK GmbH
Current assignee: BERINGER HYDRAULIK GmbH
Priority date: 1982-12-08
Filing date: 1983-12-07
Publication date: 1984-07-18
Also published as: GB8332596D0; CH665463A5; GB2165925A; FR2537693B1; GB2165925B; GB2133122B; FR2537693A1; GB8527359D0

Abstract

In a valve cartridge for insertion in a pipe to regulate flow in one direction (7) and to allow an uninfluenced flow in the opposite direction (12), the cartridge (2) has openings (6) and guides a spring-biased piston (4), which forms a control edge with the openings (6) and has radial outlet channels (18). In Fig. 1 the valve further includes an orifice plate (8) and a check valve comprising a ring (14) biassed by a spring (15) to close the radial outlet channels (18). In Fig. 2 the orifice plate (8) and ring (14) are replaced by additional radial openings (8) and a solid check valve (20) which opens the outlet channels (18) when the fluid flows in the opposite direction. <IMAGE>

Description

SPECIFICATION A flow control valve This invention relates to a hydraulic flow control valve. A flow control valve of this type is used in the case of installations which are charged on one side by external forces, in particular to ensure a charge-independent flow rate under the effect of the external forces, while during operation of the installation against the external forces the fluid flows through the flow control valve without any substantial influence.

The present invention achieves the object of designing a flow control valve of this type, preferably to be small enough so that it may be inserted into pipelines as a built-in cartridge, and consequently the fluid may flow through the pipelines in one direction of regulated flow with a substantially constant throughflow and in the opposite direction of flow with a throughflow which is substantially unchoked by the valve.

German Patent No. 2,408,422 discloses a flow control valve in which the flow-restricting function in the opposite direction of flow is cancelled and an unchoked throughflow is ensured by an orifice plate which is movable relative to the piston and rests against the piston in a form-locking manner only in the direction of regulated flow and forms a choke point, whereas in the opposite direction of flow it becomes inoperative due to its movability and releases the throughflow in a manner such that it is not choked.

According to the present invention, there is provided a flow control valve for a regulated through-flow in the direction of regulated flow and for an uninfluenced throughflow in the opposite direction to flow, comprising a cartridge which may be inserted into a pipe and which has openings on the outlet side in the direction of regulated flow which communicate with the pipe, and a piston which is guided in the cartridge, the fluid flowing through the piston in an axial direction, wherein the piston has an orifice plate therein through which the fluid flows, is supported by a spring with respect to the direction of regulated flow, forms with the openings in the cartridge a control edge on the outlet side seen in the direction of regulated flow, and has radial outlet channels which are provided upstream of the orifice plate and wherein the flow control valve further comprises a check valve comprising an axially movable ring which sits externally on the piston, which ring is pressed against a seat by a spring acting against the opposite direction of flow and, in this position, closes the radial outlet channels of the piston.

Thus, in the present invention, the orifice plate is firmly connected to the piston and produces a pressure difference in the direction of regulated flow as well as in the opposite direction of flow.

This pressure difference is used in the opposite direction of flow in order to open the one or more check valves which are positioned in a by-pass to the orifice plate.

The present invention also provides a flow control valve for a regulated throughflow in the direction of regulated flow and for an uninfluenced throughflow in the opposite direction of flow, comprising a cartridge which may be inserted into a pipe and which has openings on the outlet side in the direction of the regulated flow which communicate with the pipe, and a piston which is guided in the cartridge, the fluid flowing through the piston in an axial direction, wherein the piston is supported by a spring with respect to the direction of regulated flow, forms with the openings in the cartridge a control edge on the outlet side, seen in the direction of regulated flow, and has radial openings and outlet channels, and wherein the flow control valve further comprises a check valve provided upstream of the radial openings, seen in the direction of regulated flow, which check valve opens the outlet channels when the fluid flows through in the opposite direction of flow.

Here the radial openings serve as the abovementioned orifice plate.

Embodiments of the invention will be described in the following, by example only, with reference to Figs. 1 and 2 of the accompanying drawings which each show a longitudinal section through one embodiment of the invention.

It should be stressed that the characteristic of this embodiment resides in the fact that the check valve is connected to the piston. However, other embodiments are also possible in which the check valves are positioned in a stationary manner in the cartridge and in which the by-pass channels also lie in the cartridge.

The flow control valve which is shown in Fig. 1 may be installed in a pipe through which a fluid flows in directions 7 and 12. The direction of regulated flow in which a substantially constant, charge independent throughflow is ensured, is indicated by arrow 7. The throughflow in the opposite direction of flow 12 is substantially independent of the flow control valve, as will be explained in the following. The flow control valve comprises a cartridge 2 which may be screwed into the pipe 1 by means of a thread. A piston 4 is axially movable in the inner cylinder 3 of the cartridge 2. The piston 4 is supported by a spring 9 with respect to the direction of regulated flow 7 and it has an axial bore. The front face 5 the piston 4 forms control edges with outlet openings 6 of the cartridge. On the inlet side, the piston has an orifice plate 8 in its central channel.In the direction of regulated flow, a pressure difference is produced at the orifice plate 8 which causes the piston to be pressed against the spring force 9 in the direction of regulated flow. Since the pressure difference depends on the flow rate, a substantially constant flow is adjusted in the direction of regulated flow 7. In the example which is shown, the piston stroke is restricted by a pin 10 which is guided in a groove 11.

In the opposite direction of flow 1 2, the fluid flows through the cartridge 2 and the inner cylinder 3 thereof and the piston 4, also in an axial direction. A pressure difference is produced at the orifice plate 8 in the opposite direction, so that the openings 6 are opened to their ful) extent.

Nevertheless, choke losses occur at the orifice plate 8. In order to even out these losses, the piston has radial outlet channels 1 8 which discharge radially outwards from the central channel of the piston upstream of the orifice plate 8, seen in the opposite direction of flow 12. The channels 1 8 are closed by a check valve 13. In the embodiment which is shown, the check valve 13 is designed as a ring 14 which is closed in itself and may be moved axially on the end of the piston 4 and is supported by a spring 1 5 which acts against the opposite direction of flow 12. The front face 16 of the ring is bevelled. The foremost point thereof forms a sealing seat with the shoulder 19 of the piston.Consequently the bevelled front face 1 6, which forms with the outer casing an annular chamber with a connection to the interior of the piston, is charged with the pressure inside the piston. The opposite front face 1 7 of the ring 14 is naturally charged with the pressure of the pipe. Since a higher pressure prevails in the opposite direction of flow 12 inside the piston, i.e. upstream of the orifice plate 8, than in the pipe downstream of the orifice plate 8, the ring 14 is moved towards the spring 15 which is weak, so that the outlet channels 1 8 are opened.

In this way, the choke losses are compensated for at the metering orifice.

The embodiment according to Fig. 2 again shows the pipe with the cartridge 2 screwed therein and the piston 4 which is guided by spring force 9 on one side and by a differential pressure on the other side and which opens and closes the outlet openings 6. In its upper region, the piston has radial openings which serve as an orifice plate.

Furthermore, a body 20 which acts on a check valve and is pressed against the seat 22 by a spring 21 sits in the piston 4. The check valve is closed when the fluid flows through in the direction of regulated flow 7. When the fluid flows through the pipe 1 in the opposite direction of flow 12, the check valve is opened against the force of spring 21. Consequently, oil may also flow through the radial openings 18, by-passing the orifice plate openings 8. Reference numeral 23 denotes an adjusting screw by which the spring force 9 may be adjusted.

Claims

1. A flow control valve for a regulated throughflow in the direction of regulated flow and for an uninfluenced throughflow in the opposite direction of flow, comprising a cartridge which may be inserted into a pipe and which has openings on the outlet side in the direction of regulated flow which communicate with the pipe, and a piston which is guided in the cartridge, the fluid flowing through the piston in an axial direction, wherein the piston has an orifice plate therein through which the fluid flows, is supported by a spring with respect to the direction of regulated flow, forms with the openings in the cartridge a control edge on the outlet side, seen in the direction of regulated flow, and has radial outlet channels which are provided upstream of the orifice plate, and wherein the flow control valve further comprises a check valve comprising an axially movable ring which sets externally on the piston, which ring is pressed against a seat by a spring acting against the opposite direction of flow and, in this position, closes the radial outlet channels of the piston.

2. A flow control valve according to claim 1, wherein the ring acting as a check valve is bevelled in the region of the radial outlet channels such that an encircling annular channel is provided on the outer periphery of the piston.

3. A flow control valve for a regulated throughflow in the direction of regulated flow and for an uninfluenced throughflow in the opposite direction of flow, comprising a cartridge which may be inserted into a pipe and which has openings on the outlet side in the direction of regulated flow which communicate with the pipe, and a piston which is guided in the cartridge, the fluid flowing through the piston in an axial direction, wherein the piston is supported by a spring with respect to the direction of regulated flow, forms with the openings in the cartridge a control edge on the outlet side, seen in the direction of regulated flow, and has radial openings and outlet channels, and wherein the flow control valve further comprises a check valve upstream of the radial openings, seen in the direction of regulated flow, which check valve opens the outlet channels when the fluid flows through in the opposite direction of flow.

4. A flow control valve for a regulated throughflow in the direction of regulated flow and for an uninfluenced throughflow in the opposite direction of flow, substantially as herein described with reference to Fig. 1 or Fig. 2 of the accompanying drawings.