EP0764803B1 - Valve - Google Patents

Description

The invention relates to a valve, with a valve housing, the one supply channel for pressure medium supply, a consumer channel to connect to a consumer and has a vent channel, the Consumer duct via an inflow opening with the supply duct and via a vent with the Vent channel is connectable with two coaxial, each assigned to one of the two openings and independently movable closure bodies, each directed towards each other by spring loading are biased into a closed position in which they cover the assigned opening with a closing surface and close, and with one by means of a drive device adjustable actuating plunger for the two closure body, on the axially opposite Actuating surfaces are provided, which with appropriate Adjustment direction of the actuating plunger in opening direction against the spring force to one the closure body act.

Such a valve, designed as a pressure control valve is mentioned in the Japanese unexamined patent application the publication no. JP-H5-158552. It regulates by changing the position of the actuating plunger the adjacent to the consumer channel Print. In order to increase the pressure, that of the inflow opening assigned closure body more or less far lifted off the assigned valve seat. Corresponding takes place in relation to the other, the vent assigned closure body if the consumer side desired secondary pressure should be reduced.

In the known valve, the actuating tappet passes through one of the closure bodies and carries at its end portion a loading wall partially formed by a flexible membrane, the one hand from that in the consumer channel prevailing pressure is applied. The position of the actuating plunger is changed by changing the on the opposite wall side of the prevailing pressure.

The known valve is a pressure control valve only applicable special valve. For other valve functions it is not suitable. For example, is a 3/2 or 3/3 proportional directional valve required, must be on a completely different type of valve can be used, which is a significant cost to manufacture and Warehousing means.

It is the object of the present invention to provide a valve of the type mentioned at the beginning to create a structure owns the realization of different without much effort Allows valve types.

To solve this problem it is provided that the two Closure body axially displaceable on which it is axially penetrating actuating plunger are arranged that the two end portions projecting axially beyond the closure body of the actuating plunger at least partially formed by a flexible membrane on the valve housing side fixed gas-tight compensating wall that a respective Compensation wall and one of these facing the Closing surface of axially opposite action surface of the adjacent closure body movable boundary walls one to compensate for on the actuating plunger attacking fluidic pressure compensation chamber form, and that the two balancing spaces are connected to the consumer channel via branch channels.

Such a valve can be designed accordingly the drive device also as a pressure control valve deploy. It is also suitable however also for use as a proportional directional valve, because caused by the working fluid on the actuating plunger acting pressure forces completely balanced can be, so that even at high supply pressure only low actuating forces required for the actuating plunger are. The in the closed position of the valve in the opening direction pressure acting on the closure body is forceful balanced because the same pressure across the branch channels and the connected compensation rooms on the oppositely directed surfaces of the Closure body acts. Are also the areas of the compensating walls equal to each other, they compensate each other compressive forces also attack here. In this way is a pressure-independent actuation of the valve realizable. The actuating forces are appropriately directed essentially only according to the inherent rigidity of the membranes of the compensating walls and the one with storage and / or sealing the closure body contiguous Frictional forces and the force of the spring action of the Closure body.

The valve of the invention can be used, for example, as Use a 3/3-way directional valve, whereby a directional control can be integrated. Under certain circumstances use the valve as a simple switching valve. Use as a pressure control valve is also possible one about the selection of the area ratio of the two Compensating walls consciously have a certain resulting positioning force can specify in a direction that you can with the Counteracts drive device, thus the consumer side regulate the applied pressure. It's from Advantage that relatively large membranes can be used, if you need a large stroke without being on accordingly to have to use strong drive devices.

Advantageous developments of the invention are in the Subclaims listed.

The closure bodies are expediently designed in such a way that that those attacking them in the closed position Compressive forces exerted by the Ventilation channel depend on prevailing pressure, at least in are essentially the same size. Furthermore, the arrangement is preferably taken so that the compensation room axially opposite outer surfaces of the compensating walls are constantly exposed to atmospheric pressure. You get there thereby a practically completely compensated fluid-operated adjustment device in which both the Supply pressure as well as the outlet pressure and the ambient pressure can be compensated and no resulting Cause compressive forces.

The invention is described below with reference to the enclosed Drawing shown embodiment of the Valve explained in more detail. The only figure shows one Longitudinal section through the valve with the face attached Drive device in the form of a submersible anchor drive with integrated path control.

The exemplary valve 1 comprises a valve housing 2, to which a drive device 3 is axially attached.

In the valve housing 2 extends in the direction of Longitudinal axis 4 a receptacle 6 for a generally 5 designated adjustment device. The recording 6 goes on both ends in a housing chamber 7 larger cross section over.

In the valve housing 2 are a supply channel 10, a Consumer channel 11 and a ventilation channel 12 formed. These three channels have been axially spaced since Lich in the recording 6. The mouth 13 of the Consumer channel 11 axially between the mouths 14, 15 of the supply channel 10 and the ventilation channel 12. Im the rest all three channels 10, 11, 12 open at the other External surface of the valve housing 2, where further if necessary Pressure fluid lines are connectable.

In operation, the supply channel 10 is not in use pressure medium source shown in connection, see above that the pressure medium supply into the valve 1 he follows. The pressure medium is expediently to compressed air, in which case the valve 1 is pneumatic valve.

The consumer channel 11 allows the connection of a Pressure medium to be supplied to the consumer, for example a working cylinder. The ventilation channel 12 is used for Venting of the consumer channel 11 or the one connected to it Consumer and therefore expediently leads to the environment, with a muffler assigned to it can.

The mouths 14, 15 of the supply channel 10 and the Vent channel 12 are, for example, in the Area of annular or cylindrical extensions 16 the receptacle 6. These extensions 16 flank axially one on both sides via the mouth 13 with the consumer channel 11 communicating middle section 17 of the recording 6. The transition between the middle section 17 and the extension assigned to the supply channel 10 16 an inflow opening 18 and the transition between the middle section 17 and the one with the ventilation channel 12 communicating extension 16 a ventilation opening 19th represents.

There is one in each of the two extensions 16 piston-like closure body 22, 22 '. The two closure bodies 22, 22 'are arranged coaxially to one another and slidably supported independently. In the from the drawing resulting closed position sits respective closure body 22, 22 'with a sealing section 23 on one of the associated inflow or vent opening 18, 19 enclosing valve seat 24 so that the passage of fluid through the relevant opening 18, 19 is blocked through, the relevant opening 18, 19 of a closing surface 25 of the respective closure body 22, 22 'is covered.

Each closure body 22, 22 'is a spring device 26 assigned, via which he towards the closed position is applied. For example, it is from a helical compression spring, which is exemplary on the one hand on a circumferential radial collar 27 of the Closure body 22, 22 'and on the other hand on a surface of the valve housing 2 supports. By the spring devices 26, the two closure bodies 22, 22 'are axial facing each other in the closing direction.

The radial collar 27 lies in the area of the associated extension 16. It is adjoined by an outer cylinder contoured guide section 28 of the closure body 22, 22 ', which projects into a through opening 32 which a respective extension 16 with the neighboring one Housing chamber 7 connects. The through hole 32 is a longitudinal section of the receptacle 6, in which the closure body 22, 22 'via the assigned guide section 28 is guided axially. For sealing the through opening 32 carries each guide section 28 in the area of the outer circumference expediently in one Circumferential groove received annular seal 33 which with the circumferential surface of the through hole 32 in sliding There is a sealing contact. It can be inexpensive with a so-called 0-ring made of material rubber-elastic properties.

The closure body 22, 22 'ends at the closing surface 25 axially opposite end face with an action surface 34, the size of the amount expediently corresponds to the closing surface 25. The one another identical cross-sectional areas of the two through openings 32 correspond to the embodiment Cross sections of the inflow opening 18 and the vent opening 19th

In addition to the two closure bodies 22, 22 ' Adjustment device 5 also a rod-shaped Actuating plunger 35, which is arranged coaxially in the receptacle 6 is. The one-piece actuating plunger, for example 35 penetrates both closure bodies simultaneously 22, 22 ', which thus sit on the actuating plunger 35, whereby a relative axial displaceability is guaranteed is.

The two closure bodies 22, 22 'are axially spaced arranged to each other. The one that bridges this gap Section of the actuating plunger 35, hereinafter referred to as Bridging section 36 is designated with two radial projections 37 provided that, for example, revolving like a ring or are collar-shaped. One each Radial projection 37 is immediate to a closing surface 25 upstream. Each radial projection 37 has the associated closure body 22, 22 'facing the axial side via an actuating surface 38. The arrangement is so met that in the closed position of both closure bodies 22, 22 'of the associated radial projection 37 with its Actuating surface 38 just on the relevant closure body 22, 22 'is applied.

The actuating plunger 35 can be used with the help of the mentioned Axially move or adjust drive device 3. Depending on the direction in which the adjustment movement starts from the neutral position shown and explained of the actuating plunger 35, one of the Closure body 22, 22 'by the action of the associated Radial projection 37 lifted out of the closed position and shifted to an open position in which its sealing section 23 a more or less large distance from the Valve seat 24 complies. The other closure body is not affected, since the one assigned to it Radial projection 37 axially away from it.

The actuating plunger 35 projects out of the closure body arrangement on both sides 22, 22 'with an end section 42, 42' out and into the adjoining housing chamber 7. Bears inside the relevant housing chamber 7 each end section 42, 42 'a gas-tight compensating wall 43, which seals the housing chamber 7 in two axially successive rooms divided. The immediately to the through opening 32 space as Compensation space 44, the opposite outer space as Outside space 45.

The compensating wall 43 is on the one hand at the end section 42, 42 'and on the other hand fixed to the valve housing 2. The arrangement is such that the actuating plunger 35 can nevertheless perform an axial movement. This results from the fact that the compensating wall 43 at least in part by a flexible membrane 46 is formed. This, for example, disc-shaped Membrane, suitably made of material with rubber elastic Has properties, has in the embodiment a central opening 47 with which it opens the actuating plunger 35 is attached and clamped. In the area of its outer peripheral edge it is in the Area of the peripheral wall of the housing chamber 7 tightly clamped.

The tappet-side attachment takes place in the exemplary embodiment expediently by means of two axially flanking support disks 49, between which they with the Edge of its central opening 47 is clamped. These support disks 49 can be radially very close to the Project circumferential surface of the housing chamber 7.

Due to the sealing of the compensation space 44 with the help a membrane 46 will prevent the occurrence of friction when adjusting of the actuating plunger 35 prevented. The to be applied Adjustment forces only have to be large enough that the inherent rigidity of the membranes 46 is overcome can be.

To the adjacent supply duct 10 and ventilation duct 12 is a respective compensation space 44 over the annular Seal 33 sealed, which in the through opening 32 protruding closure bodies 22, 22 ' wearing.

The compensation wall assigned to a respective compensation space 44 43 and loading surface 34 form movable ones Boundary walls of the compensation room concerned 44. The pressure prevailing in the compensation chamber 44 is applied thus both the inner surface facing the compensation space 44 52 of the compensating wall 43 and the facing Actuation surface 34 of the adjacent Closure body 22, 22 '.

Inside the valve housing 2 there are also two Branch channels 53 are provided, both of the consumer channel 11 and branch into one of the equalization rooms 44 flow into. This ensures that the Consumer channel 11 prevailing pressure at the same time in two compensation rooms 44 is pending.

The two outer spaces 45 are expediently each connected with the environment, for what purpose appropriate Connection channels 54 may be present. To this The compensation chamber 44 is axially opposite Outer surface 55 of the compensating wall 43 constantly from atmospheric pressure acted upon.

Consider the neutral position shown in the figure of the valve 1, so is the adjusting device 5 with respect the pressure forces caused by the working fluid practically completely compensated. On every closure body 22, 22 'is both on the closing surface 25 as also - via the branch duct 53 and the compensation space 44 - on the loading surface 34 of the output or consumer pressure, though because of the area identity no resulting actuating forces occur.

In addition, the closure body controlling the inflow opening 18 22 Compressed force compensated with regard to the supply pressure. That in the assigned extension 16 prevailing pressure exposed, oval opposing closure body surfaces 56, 56 ', which in the present case are on the radial collar 27 are the same size. The same applies to the closure body controlling the vent opening 19 22 ', so that there is also compensation on the vent side. The closing force acting on the closure bodies 22, 22 ' is applied solely by the spring devices 26.

In addition, the inner surfaces 52 of the compensation walls 43 are identical to each other, as are the outer surfaces 55, are also on the actuating plunger 35 via the Compensating wall 43 attacking axial forces neutralized.

In order to actuate valve 1, the actuating tappet 35 with the aid of the drive device 3 from its neutral position deflected in one direction or the other. The In the exemplary embodiment, force is introduced via a plunger 57 of the drive device 3, which on the one (42 ') of the two end portions of the operating plunger 35 attacks. In the embodiment there is a firm connection before, so that both compressive forces as well Tractive forces are transferable.

It is advantageous that the adjusting force to be applied when Embodiment regardless of the pressure of the working fluid is. This also applies if either the inflow opening 18 or the vent 19 more or is less open.

For example, the actuating plunger 35 is based on the neutral position shown shifted to the right, see above the inflow opening 18 is open and fluid can flow out of the Flow supply channel 10 to consumer channel 11. The Vent opening 19 is still closed. With Exception of the closure body surfaces 56, 56 'on the vent side Closure body 22 ', which thus continues is compensated for ambient pressure, is now due to the closing surfaces 25 and loading surfaces 34 of the closure body 22, 22 'as well as on the inner surfaces 52 of the Compensation walls 43 of the prevailing in the supply channel Pressure, so that, just at a higher pressure level, there is a compensation of the pressure forces. The actuating forces required for actuation are therefore also at least essentially from the valve position independently.

In the exemplary embodiment, the drive device 3 is included an electromagnet device 58 equipped as Submersible anchor drive device is executed. Corresponding that supplied to the electromagnet device 58 Amperage here takes the plunger 57 a certain Axial position. A more detailed description of the submersible drive mechanism needless here because you Structure as such is known to the person skilled in the art. In the embodiment a path sensor 61 is integrated, so that itself in connection with a not shown Control device can implement a path control. On so-called proportional operation is easily possible, in which the actuating plunger 35 can be positioned continuously is.

The design of the drive device 3 is fundamental any. For example, you could have one include so-called proportional magnets, its armature works as a plunger 57 and mechanical pressure forces can initiate in the actuating plunger 35, wherein Provision a spring device can be provided the one on the opposite end against the one there existing compensation wall 43 works.

It would be to get a resulting restoring force also conceivable, the surfaces of the compensation walls 43 are not to choose the same size, but a certain area difference to provide. This enables use in particular a weak drive with a large stroke.

In particular with a configuration as described above, the valve can be used as a pressure control valve become. In connection with a consumer channel 11 assigned pressure sensor can control here occur that always a certain consumer side Outlet pressure is present.

The valve can not only be used as a proportional directional valve, but also use as a simple switching valve, in which the closure body only between two Positions are switchable and no intermediate positions can take. The benefits of compensation fluidic pressure forces also remain here receive. You can do different without much effort Realize valve types.

Claims (9)

1. Valve with a valve housing (2) provided with a supply passage (10) for the supply of pressure medium, an actuator passage (11) for connection to an actuator and a breather passage (12), the actuator passage (11) being connectable to the supply passage (10) via an inlet port (18) and to the breather passage (12) via a breather port (19), with two coaxial and independently movable closing bodies (22, 22'), each assigned to one of the ports (18, 19) and biassed by spring pressure towards a closed position in which it covers and closes the port (18, 19) to which it is assigned with a closing surface (25), and with an operating plunger (35) for the two closing bodies (22, 22'), which is controllable by means of a drive unit (3) and provided with opposing operating surfaces (38) which, depending on the control direction of the operating plunger (35), act on either of the closing bodies (22, 22') in the opening direction against spring pressure, characterized in that the two closing bodies (22, 22') are arranged to be axially movable on the operating plunger (35) passing through them in the axial direction, in that the two end sections (42, 42') of the operating plunger (35), which project axially beyond the closing bodies (22, 22'), support a gas-tight compensating wall (43) formed at least in part by a flexible diaphragm (46) and fixed to the valve housing, in that each compensating wall (43) and the facing pressurizing surface (34) of the adjacent closing body (22, 22'), which lies axially opposite the closing surface (25), together form movable boundary walls of a compensating chamber (44) for balancing the pressures applied to the operating plunger (35), and in that the two compensating chambers (44) are connected to the actuator passage (11) via branch passages (53).
2. Valve according to claim 1, characterized in that each closing body (22, 22') is so designed that the axially opposed closing body surfaces (56, 56') on which the pressure in the associated supply or breather passage (10, 12) acts in the closed position are of equal size.
3. Valve according to claim 1 or 2, characterized in that each closing body (22, 22') is provided with a cylindrical guide section (28) enclosing the operating plunger (35), which guide section is, with the interposition of an annular seal (33), arranged to be axially movable in a through passage (32) running between the associated supply or breather passage (10, 12) and the associated compensating chamber (44).
4. Valve according to claim 3, characterized in that the pressurizing surface (34) is formed by the end face of the guide section (28).
5. Valve according to any of claims 1 to 4, characterized in that the drive unit (3) is located in the area of one of the axial faces of the valve housing (2) and provided with an actuating plunger (57) acting together with the operating plunger (35).
6. Valve according to claim 5, characterized in that the drive unit (3) is provided with a solenoid device (58).
7. Valve according to claim 6, characterized in that the drive unit is a solenoid plunger drive unit.
8. Valve according to any of claims 1 to 7, characterized in that atmospheric pressure continuously acts on the external surfaces (55) of the compensating walls (43) which are located axially opposite the compensating chamber (44).
9. Valve according to any of claims 1 to 8, characterized in that the internal surfaces (52) of the two compensating walls (43) which face each compensating chamber (44) are different in size.

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