CN108692176B - Condensate drain valve and maintenance device for compressed air production - Google Patents

Abstract

The invention relates to a condensate drain valve with a valve housing and a piston assembly accommodated in a linearly movable manner therein, which piston assembly comprises a first working piston which is traversed by a fluid channel, in which a valve seat for a valve member is formed, and which piston assembly comprises a second working piston which separates a first fluid region from a third fluid region which is delimited by the valve housing and which is in communicative connection with the first fluid region via a connection opening, with a float which is arranged in the first fluid region and in which a valve element is mounted which can selectively seal or release the connection opening, wherein the piston assembly is traversed by the connection channel which extends between the first fluid region and the second fluid region, and with an actuating element which, in a functional position of the piston assembly, traverses the fluid channel in the region of the valve seat and removes the valve member from the valve seat.

Description

Condensate drain valve and maintenance device for compressed air production

Technical Field

The invention relates to a condensate drain valve (kondetablalassventil) for a compressed air maintenance device (Druckluff ä t) and a maintenance device for compressed air production (Druckluferfheiting).

Background

Document DE 10 2014 012 A1 discloses a liquid discharge device and a maintenance device equipped with the same, wherein the discharge valve can either block or release a discharge channel depending on the level (Pegelstand) of the liquid accumulating in the receiving chamber, and wherein for operating the discharge valve there is a control valve having a float-operable control valve element which cooperates with a valve seat associated with the control channel, wherein the float and the control valve element are combined into a uniformly pivotable pendulum unit with respect to the valve seat, the lifting force of the liquid in the receiving chamber being able to exert a torque in order to lift the control valve element from the valve seat.

Disclosure of Invention

The object of the invention is to provide a condensate drain valve and a servicing device for compressed air production with an improved functional range.

This object is achieved for a condensate outlet valve of the type mentioned at the outset with the features described below. It is provided here that the condensate drain valve has a valve housing which is penetrated by a recess in which a piston assembly is accommodated in a linearly movable manner along a movement axis between a first functional position and a second functional position, wherein the piston assembly carries a first working piston which bears radially sealingly in the recess, separating the first fluid region from the second fluid region, wherein the first working piston is traversed by a fluid passage which extends between the first and second fluid regions and which comprises a valve chamber, in the valve chamber, a valve seat for the sealed mounting of the valve element is formed and a movable valve element is accommodated in the valve chamber, wherein the piston assembly carries a second working piston which bears linearly movably and radially sealingly in the recess, separating the first fluid region from the third fluid region, wherein the third fluid region is bounded by the valve housing and is in communicative connection with the first fluid region via a connection opening, and wherein a float is provided which is arranged in the first fluid region and which is supported in a linearly movable manner between a lowered position (Absenkstellung) and a raised position (Auftriebsstellung) at the valve housing, where the valve element is mounted, the valve element seals the connection opening in the lowered position and releases the connection opening in the raised position, wherein the piston assembly is traversed by a connecting channel which extends between the first and the second fluid region and in which an actuating element is mounted at the valve housing, in the second functional position of the piston assembly, the actuating element passes through the fluid channel in the region of the valve seat and lifts the valve collar from the valve seat, in the second functional position, a connection is thus present in fluid communication between the first fluid region and the second fluid region.

The condensate drain valve is preferably used in the bottom region of a catch vessel (Auffangbeh ä filter) of a compressed air maintenance device, wherein the catch vessel is arranged below a separating device with which moisture is separated from the pressure-loaded fluid to be prepared. The task of the condensate drain valve is to automatically initiate the discharge of the liquid collected in the catch vessel without operator intervention being required for this purpose.

In this case, it is provided that a first fluid region, which is determined in particular by the trapping vessel (auffangef ä beta), is acted upon by the operating pressure of the pressure-loaded fluid, for the production of which a compressed air maintenance device is used. It is provided as an example that during regular operation of the compressed air maintenance device, in which compressed air preparation is to take place, the pressure difference between the operating pressure and the ambient pressure prevailing in the second fluid region lies in the range from 1 bar to 15 bar. It is furthermore assumed that the ambient pressure prevailing in the second fluid region is at least substantially equal to or equal to the atmospheric air pressure.

The condensate drain valve establishes a temporary fluid-communicating connection between the first fluid region (in which separated moisture also collects) and the second fluid region depending on the level of a liquid mirror (flessigkeitsspiege) that can collect in the capture vessel. In this way, the liquid collected in the capture vessel is discharged through the fluid channel into the second fluid region, using a sufficient pressure difference between the first fluid region and the second fluid region.

A positive coupling (zwangkoppling) is present between the first working piston and the second working piston, so that a movement of the second working piston always also results in a movement of the first working piston.

The movement of the second working piston and therefore the piston assembly from the first into the second functional position is brought about by the fact that the compression force of the fluid present in the third fluid region on the second working piston is greater than the oppositely directed compression force acting on the piston assembly. This can occur as long as the inflow of fluid from the first fluid region into the third fluid region through the connection opening is less than or equal to or greater than the outflow of fluid from the third fluid region into the second fluid region, which is achieved by a connection channel which extends between the first and second fluid regions.

Such fluid inflow occurs as soon as the valve element releases the connection opening between the first fluid region and the third fluid region, which is achieved by the movement of the float from the lowered position into the raised position.

The movement of the float in the case of a correct spatial orientation of the condensate drain valve depends on the level of the liquid mirror, which collects in the compressed air maintenance device by separating the moisture from the pressure-loaded fluid in the catch vessel, at the bottom of which the condensate drain valve can be arranged.

Since, in the case of a horizontal lowering of the liquid level, a movement of the float floating on the liquid from the raised position into the lowered position is effected, the valve element articulated on the float in turn bears sealingly against the connection opening, so that the connection opening is closed again and the fluid inflow from the first fluid region into the third fluid region is interrupted. The operating pressure prevailing in the third fluid region, which is also prevailing at the point in time of the interruption of the fluid inflow from the first fluid region into the third fluid region, is relieved via the connecting channel. Movement of the piston assembly from the second functional position into the first functional position is thereby effected. The valve element is therefore again in sealing contact with the valve seat, since the actuating element (which in the second functional position of the piston assembly passes through the fluid channel in the region of the valve seat and lifts the valve ring from the valve seat) no longer acts on the valve member, so that the fluid channel is again sealed off.

It is preferably provided that the cross section of the connecting opening is at least 2 times, preferably 4 times, particularly preferably 8 times, the cross section of the connecting channel. This ensures that, in the event of a release of the connection opening by the valve element, a rapid pressure buildup in the third fluid region can be carried out, as a result of which the desired movement of the piston assembly from the first into the second functional position and the release of the fluid channel by the interaction between the actuating element and the valve ring also take place. In addition, it is thereby ensured that, after the connection opening has been closed off by the valve element, the pressure which is removed by the fluid flowing through the connection channel from the third fluid region into the second fluid region is relieved within a relatively short time span. Thereby, unnecessary fluid loss from a fluid system equipped with a service device including a condensate drain valve is effectively prevented.

Advantageously, when a pretensioned spring means, in particular a helical spring, is arranged between the piston assembly and the valve housing, it determines one of the two functional positions of the piston assembly (in particular the second functional position) as the preferred position. The condensate drain valve is thus in a predefinable functional position without the effect of external influences, such as, for example, pressure differences between the first and second fluid regions. It is preferably provided that the spring means are arranged between the piston assembly and the valve housing in such a way that the piston assembly is arranged in the second functional position without external influences. This measure ensures that the condensate drain valve, when used in a service device, releases the fluid channel between the first fluid region and the second fluid region in the case of a first pressure-free service device. Accordingly, in the case of a pressure-free service device, it is ensured that liquid can flow away from the catch container of the service device via the open fluid channel. When the operating pressure is applied to the maintenance device, the resulting force acts on the piston assembly, which is derived from the difference between the compression force acting on the first piston assembly and the compression force acting on the second piston assembly, both of which are each acted upon by the fluid pressure in the first fluid region. Preferably, the surface on which the fluid acts of the second piston assembly is larger than the surface on which the fluid acts of the first piston assembly, so that the resulting force acts counter to the compressive force of the spring means and a transfer of the piston assembly from the second functional position into the first functional position is achieved. The valve seat formed in the first piston assembly is thereby spaced apart from the actuating element, so that the valve member bears sealingly against the valve seat and blocks the fluid passage. Since no liquid should be present at this point in time, the float is in the lowered position, so that the connection opening is closed by the valve element and the same pressure as the second fluid region is present in the third fluid region as a result of the permanent fluid connection to the second fluid region. In the third fluid region, a pressure increase due to the linear relative movement of the piston assembly with respect to the valve housing likewise does not occur, since the fluid displaced in the third fluid region by the second working piston can flow away into the second fluid chamber via the connecting channel. It is particularly preferred that the spring means is designed as a helical spring, wherein the central axis of the helical spring is designed parallel to the axis of movement of the piston assembly. It is provided by way of example that at least one of the two working pistons is of rotationally symmetrical design and that the center axis of the helical spring is oriented relative to the axis of rotational symmetry of the rotationally symmetrical working piston.

In a further embodiment of the invention, it is provided that the actuating element is movably received at the valve housing and/or is designed as a coupling (Anschlusskupplung) for a fluid line, in particular a fluid hose. Preferably, the actuating element is accommodated in a linearly movable manner at the valve housing, wherein the axis of movement for the actuating element is preferably oriented parallel to the axis of movement of the piston assembly. Furthermore, it is provided in this case that the axial movability of the actuating element is limited by suitable stops, so that the actuating element is preferably arranged at the valve housing in a non-variable manner. The path of movement for the actuating element is selected by the stop in such a way that, in the event of a movement of the actuating element from the first functional position (in which the actuating element does not pass through the valve seat in the valve chamber and thus does not lift the valve ring from the valve seat, as long as the piston assembly is in the first functional position) into the second functional position, a lifting of the valve ring from the valve seat can be brought about, even when the piston assembly is in the first functional position. By this measure, a manual opening of the fluid channel and a corresponding withdrawal of liquid from the first fluid region can thereby be forced, even when the liquid level in the first fluid region does not yet cause the float to float into the raised position, in which the valve element releases the connection opening. In addition or alternatively, the actuating element can be designed as a coupling for a fluid line in order to ensure an orderly flow-off of the liquid from the first fluid region, for example into a suitable vessel.

In an advantageous development of the invention, it is provided that the connection opening is formed at an end shield of the sleeve section of the valve housing, in particular at the apex of the end shield, wherein the path of movement of the float between the lowered position and the raised position is oriented parallel, in particular coaxially, with respect to the longitudinal axis of the sleeve section. The sleeve section has a dual function in that it serves on the one hand as a guide pin for the linear guidance of the float, which preferably is penetrated at least in sections by a recess, which is configured to receive the sleeve section of the valve housing in order to ensure the linear guidance. On the other hand, the sleeve section comprises an end shield which is mounted on the end face, in particular in one piece, and in which a connection opening is formed. This ensures an advantageous mounting of the valve element on the float and a reliable interaction of the valve element with the connecting opening.

The valve element is expediently mounted on the float so as to be movable, in particular so as to be pivotable. This makes it possible for the float to pass through a path of movement with a predefinable path length from the lowered position before the valve element also only partially releases the connection opening. It is particularly advantageous if the valve element is pivotably articulated on the float, since this allows the movement path to be implemented with a large path length from the lowered position to the release connection opening, for which a stable operating condition for the condenser outlet valve (betriebsweese) can be ensured.

In a further embodiment of the invention, it is provided that the pivot axis for the valve element is oriented transversely to the longitudinal axis of the sleeve section. By means of this orientation of the pivot axis, an advantageous downward movement of the valve element on the end shield of the sleeve section is achieved, so that a reliable sealing of the connection opening by the valve element is ensured in the lowered position of the float.

In an advantageous development of the invention, it is provided that the distance between the pivot axis of the valve element and the bearing region of the valve element on the connection opening corresponds at least substantially to the distance between the lowered position and the raised position of the float. In this way, a compact design for the float and a valve element with a reliable mounting of the valve element on the end shield of the sleeve section are advantageously combined for sealing the connection opening at least until shortly before the raised position is reached.

It is preferably provided that the fluid contact surface of the second working piston in the third fluid chamber is at least 1.5 times, preferably 2 times, particularly preferably 2.5 times, greater than the fluid contact surface of the first working piston in the first fluid chamber.

The object of the invention is achieved for the following features of a maintainer of the type mentioned at the outset. The servicing device comprises a catch container for the liquid and a separating device for separating the liquid from the compressed air flow and a condensate drain valve according to the above, wherein the valve housing of the condensate drain valve is sealingly accommodated in a recess of the catch container on the bottom side and wherein the first fluid region is delimited by the catch container.

Drawings

An advantageous embodiment of the invention is represented in the drawing. Here:

figure 1 shows a partially illustrated cross-sectional view of a service device with a condensate drain valve,

figure 2 shows a detail of the piston assembly received in the valve housing,

figure 3 shows a detail of the buoy.

Detailed Description

Fig. 1 shows a partially schematic representation of a service device 1, which service device 1 can be used in a compressed air supply system not shown in greater detail and is configured purely exemplarily for moisture separation according to the representation of fig. 1. In other, non-represented embodiments of the maintainer, it may also include a pressure regulating valve and/or a compressed air oiler (Druckluft- Ö ler). This additional function is however of secondary significance at any time for the condensate outlet valve 2 described in more detail below and is not explained in more detail.

The servicing device 1 comprises a housing 3, which housing 3 delimits a separating chamber 4, wherein a moisture separator 7, which is only shown purely schematically, is arranged in the upper part of the housing 3 between an inlet connection 5 and an outlet connection 6, which moisture separator 7 is configured in particular as a separating cyclone. The moisture separator has the task of separating moisture from the compressed air flow which can flow from the inlet connection 5 to the outlet connection 6 and of capturing the separated moisture in the form of a liquid mist or liquid droplets in the separation chamber 4. Here, the lower portion of the housing 3 serves as a catch container. The maintenance device 1 is dependent on the correct functioning being oriented at least substantially vertically to the central axis 8, i.e. in a direction perpendicular to the ground surface, within a predetermined angular tolerance range, so that separated liquid can collect at the bottom 9 of the housing 3 and an increased liquid level can be used which is not shown in greater detail for the operating principle of the condensate drain valve 2 described in greater detail below.

The condensate outlet valve 2 is accommodated purely by way of example in a non-positive fit in a recess 10 in the base 9 of the housing 3, wherein the recess 10 is designed as a stepped bore (stuffenbohung) in an exemplary manner and, proceeding from the wall section 11, has a radially inwardly projecting annular collar 12, which annular collar 12 prevents an axial movement of the condensate outlet valve 2 accommodated in the recess 10.

As can be gathered from fig. 1, the condensate drain valve 2 comprises a plurality of components, the type of construction, function and interaction of which shall be described in more detail in particular in connection with fig. 2 and 3.

The basic components of the condensate drain valve 2 are a valve housing 15, a piston assembly 16, a valve collar 17, a float 18 and a valve element 19.

Exemplarily, the valve housing 15 comprises a lower part 20 and an upper part 21, which are ensured purely by a positive-locking connection between the latching groove 22 formed circumferentially at the lower part 20 and the latching collar 45 formed circumferentially at the upper part 21. Due to the type of construction of the two parts of the valve housing 15, a cost-effective production of both the lower part 20 and the upper part 21 is achieved, in particular, in the plastic injection molding method. On the other hand, this also enables a simple assembly of the piston assembly 16, which is accommodated in the working recess 24 of the valve housing 15 in a linearly movable manner along the movement path 23. From fig. 2, which shows an enlarged illustration of the lower part 20 of the valve housing 15 and the components received and mounted therein, it is apparent that the lower part 20 has a plurality of differently profiled wall sections which are at least partially of significance as functional surfaces for the operating principle of the condensate drain valve 2.

The first wall section 27 of the lower part 20, which is configured in an exemplary rotationally symmetrical and cylindrical manner relative to the center axis 8, is turned outward in the radial direction and is provided with a circumferential groove 28, which circumferential groove 28 serves to accommodate a sealing ring 29. The first wall section 27 is dimensioned such that it can be fitted into the recess 10 of the housing 3 with a displacement movement. In this case, the sealing ring 29 is in sealing contact with the wall section 11 of the recess 10 by elastic deformation. Adjacent to the first wall section 27, a second wall section 30 is arranged which turns outward in the radial direction, is configured purely by way of example rotationally symmetrically and cylindrically relative to the center axis 8 and has an outer diameter which is matched to the inner diameter of the annular collar 12 in such a way that the second wall section 30 can be accommodated in the annular collar 12 at least virtually without play with respect to the radial direction. Furthermore, the lower part 20 has a radially inwardly directed third wall section 31, which is configured purely by way of example rotationally symmetrically and cylindrically with respect to the central axis 8, which is configured for displaceable and sealed accommodation of a first working piston 32 of the piston assembly 16. In the axial direction, three further wall sections 33, 34 and 35 are connected to the third wall section 31, each of which is configured rotationally symmetrically and cylindrically with respect to the center axis 8. The fourth and sixth wall sections 33 and 35 have a smaller diameter than the third wall section 31, and the fifth wall section 34 has a smaller diameter than the wall sections 33 and 35 themselves. Thus, for example, the fourth wall section 33 forms an axial stop for the first working piston 32 and thus limits the downward movement path 23 of the piston assembly 16 in the axial direction.

The first wall section 27 is a sleeve-like, axially upwardly projecting end region 36 of the lower part 20, which extends in the axial direction until it exceeds the latching groove 22. Purely by way of example, the end region 36 is penetrated by a bore 37 oriented transversely to the central axis 8, which bore 37 ensures a fluid-communicating connection between the working recess 24 in the valve housing 15 and the surroundings.

In the case of the arrangement of the condensate drain valve 2 in the housing 3, the separating chamber 4 represented in fig. 1 forms a first fluid region 40, which is permanently connected to the working recess 24 of the valve housing 15 via the bore 37. The upper part 21 is configured purely by way of example rotationally symmetrically with respect to the central axis 8 and comprises a first sleeve section 41, an annular connecting section 42 and a second sleeve section 43 with an end cap 44. The first sleeve section 41 is provided at a radially outwardly directed outer surface with a snap collar 45, which is configured for fixing in the snap groove 22 of the lower part 20. The radially inwardly directed inner surface 46 of the first sleeve section 41 forms a linearly movable and sealing abutment for a second working piston 60 of the piston assembly 16. The second sleeve section 43 has a significantly smaller diameter than the first sleeve section 41, wherein the difference in diameter between the two sleeve sections 41 and 43 is overcome by the annular connecting section 42. The diameter of sleeve section 41 is purely exemplary 2 to 4 times the diameter of sleeve section 43.

The second sleeve section 43, which is purely exemplarily of slightly conical configuration, tapers at an increasing distance from the first sleeve section 41. The taper angle for the second sleeve section can be selected, for example, in the range from 0.5 to 3 degrees and serves, on the one hand, as a draft angle (Entformschr ä ge) for the production of the upper part 21 in the plastic injection molding method and, on the other hand, ensures an advantageous guidance for the buoy 18. Purely by way of example, the axial extension of the second sleeve section 43 is 2 to 8 times, in particular 5 times, the axial extension of the first sleeve section 41.

An end shield 44 is arranged at the end region of the second sleeve section 43 facing away from the first sleeve section 41, which end shield 44 closes the sleeve section 43 as far as the connection opening 47. Purely by way of example, it is provided that the end shield 44 is convexly curved at the outer surface 48 and comprises a support 49 which is arranged centrally and thus coaxially with respect to the center axis 8 and is penetrated by the connection opening 47. The annular end face 50 of the support 49 serves as an abutment surface for the valve element 19 belonging to the float 18 and thus forms a sealing surface, provided that the valve element 19 is in the appropriate orientation relative to the support 49.

The piston assembly 16 accommodated in the working recess 24 of the valve housing 15 is designed as a double piston (Doppelkolben) with a first working piston 32 and a second working piston 60. The first working piston 32 is determined by an annular collar 54 and a piston seal 55 in the form of a lip seal ring (lippendlichring), the diameter of which is adapted to the third wall section 31 of the valve housing 15 in such a way that the first working piston 32 bears in a linearly movable manner in a sealing manner against the third wall section 31. The first working piston 32 separates the first fluid region 40 from a second fluid region 56, the second fluid region 56 being external to the maintenance device 1.

The second working piston 60 is delimited by a circumferential annular collar 61 and an axially spaced annular collar 62, which delimit an annular groove 63, in which annular groove 63 a rubber-elastic sealing ring 64 is accommodated. The annular collar 61 and the sealing ring 64 are adapted to the radially inwardly directed inner surface 46 of the first sleeve section 41 in such a way that the second working piston 60 bears in a linearly movable sealing manner against the inner surface 46. The second working piston 60 separates the first fluid region 40 from a third fluid region 57, which third fluid region 57 is separated from the first fluid region 40 purely by way of example by the upper part 21.

Furthermore, it is provided that the piston assembly 16 has a recess 66 which is oriented coaxially with respect to the center axis 8 and extends in the axial direction from the circular piston surface 65, which recess 66 is configured purely by way of example rotationally symmetrically with respect to the center axis 8. In the recess 66, a spring means, which is embodied in an exemplary manner as a helical spring 67, is accommodated, which is supported at a circular bottom face 68 of the piston assembly 16 and at an opposite annular inner surface 69 of the upper part 21 and has an internal prestress at all times, independently of the position of movement of the piston assembly 16 along the movement path 23. Proceeding from the bottom surface 68, the connecting channel 70 extends in the axial direction into the second fluid region 56.

Purely by way of example, a throttle 71 is arranged in the connecting channel 70 configured as a through-bore, which throttle 71 has a defined cross section with a high degree of accuracy. It is provided by way of example that the cross section of the connecting opening 47 is at least 2 times, preferably 4 times, particularly preferably 8 times, the cross section of the throttle element 71. The connecting channel 70 is arranged eccentrically with respect to the center axis 8, in order to provide sufficient space in the region of the first working piston 32 for a fluid channel 72, which fluid channel 72 extends from the first fluid region 40 between the components of the condensate drain valve 2 as far as the second fluid region 56. The fluid channel 72 can be traversed by a fluid, in particular by condensed water and by compressed air, and is symbolized purely by way of example by a fluid path (fluididfad) 95. Purely by way of example, the fluid channel 72 extends from the first fluid region 40 via a transverse bore 73, which is axially above the piston seal 55 and is oriented exemplarily transversely to the center axis 8, up to a longitudinal bore 74, which is oriented coaxially with respect to the center axis 8, the longitudinal bore 74 emerging at the end face in the second fluid region 56.

In the fluid channel 72, a valve chamber 75 is formed, which has a significantly larger cross section than the transverse bore 73 and the longitudinal bore 74 and which is designed purely as a cylindrical recess formed coaxially with respect to the center axis 8. At the transition between the valve chamber 75 and the longitudinal bore 74, an exemplary conical segment-shaped valve seat 76 is provided, which is designed for the sealed mounting of the purely exemplary conical valve ring section 17. The valve element 17 is preferably made of a rubber-elastic material and is accommodated in the valve chamber 75 in a freely movable manner.

As can be seen from the illustration in fig. 1 and 2, the lower part 20 of the valve housing 15 has associated therewith a sleeve-like coupling element 78 which is geometrically matched to the sixth wall region 35 of the valve housing 15 in such a way that the coupling element 78 is accommodated in a displaceable manner at the lower part 20. At the upper end region, the coupling element 78 is provided with a plurality of latching noses 69 which are arranged in the circumferential direction and project outward in the radial direction and which grip behind the inwardly projecting fifth wall region 34 of the lower part 20 and thus enable the linear gap adhesive (linear belt) mounting of the coupling element 78 at the lower part 20.

The coupling element 78 is penetrated by a longitudinal recess 80, which longitudinal recess 80 enables a fluid flow through the coupling element 78 along the central axis 8. In the longitudinal recess 80, a bayonet-like actuating element 81 is arranged, which is oriented at least substantially parallel to the central axis 8 and is provided with a tip 82 tapering in the direction of the valve chamber 75. The actuating element 81 is designed such that it does not pass through an opening bordered by the valve seat 76 in the first functional position of the piston assembly 16 (as it appears in fig. 2) and it passes through an opening bordered by the valve seat 76 in the second functional position of the piston assembly 16 (as it appears in fig. 1).

This achieves that, in the event of a linear movement of the piston assembly 16 from the first functional position according to fig. 2 (in which the valve ring 17 rests sealingly on the valve seat 76 and thus blocks the fluid passage 72) into the second functional position, a force introduction of the actuating element 81 onto the valve ring 17 is effected, so that this valve ring 17 is lifted off the valve seat 76 and the fluid passage 72 is released.

The buoy 18 represented in fig. 1 and 3 is configured purely by way of example as a rotationally symmetrical hollow body of the Torus (Torus) type and has an extension along the central axis 8 which at least substantially corresponds to the outer diameter of the buoy 18. The recess 85 formed centrally in the float 18 is matched in terms of its dimensioning to the sleeve section 43 of the upper part 21 in such a way that the sleeve section 43 can serve as a guide track for the float 18. Purely by way of example, the float 18 is produced from an upper part 86 produced in a plastic injection molding method and a lower part 87 of annular design which is materially fittingly mounted on the upper part 86.

At an end region 88 above the upper part 86, a valve well 89 is formed, which has a U-shaped profile (profiling) oriented transversely to the center axis 8. At the wall 90 (whose non-illustrated surface normal is oriented transversely to the center axis 8 and perpendicularly to the illustrated plane of fig. 1 and 3), the valve element 19 is mounted so as to be pivotable about a pivot axis 91, which is also oriented transversely to the center axis 8 and perpendicularly to the illustrated plane of fig. 1 and 3 and is illustrated purely symbolically.

Starting from the sealing position shown in fig. 3 (in which the valve element 19 bears sealingly against the connection opening 47 of the second sleeve section 43), the valve element 19 can execute an oscillating movement counter to the clockwise direction in the case of a linear movement of the float 18 from the lowered position according to fig. 3 into the raised position according to fig. 1 and is lifted from the connection opening 47 in the process. Correspondingly, by this linear movement of the float 18, the connection opening 47 is released and a fluid flow can be achieved from the first fluid region 40 into the third fluid region 57 limited by the upper part 21 and by the second working piston 60.

In order to keep contaminants away from the float 18, the float 18 is surrounded by a mesh hood 92, which mesh hood 92 is fixed in a form-fitting manner at the upper end region 36 of the lower part 20 and which is provided with perforations not shown in greater detail, in order to achieve an exchange of liquid through the mesh hood 92 and at the same time keep contaminant particles brought into the first fluid region 40 away from the float 18.

The working principle of the service device 1 in the case of application in a compressed air system not represented can be described as follows:

first, the servicing device 1 is coupled with its inlet coupling 5 to the compressed air source and with its outlet coupling 6 to the compressed air sink (drucklufenke), wherein the piston assembly 16 is in the second functional position due to the compression force of the helical spring 67, as it appears in fig. 1, as long as the supply of compressed air by the compressed air source has not yet been achieved. At this point in time, the first fluid region 40, the second fluid region 56 and the third fluid region 60 are at the same pressure level, so that the force generated by the compressive force on the piston assembly 16 disappears and only the compressive force of the coil spring 67 acts on the piston assembly 16.

Due to the geometric design of the lower part 20 and the piston assembly 16 (in particular the transition between the third wall section 31 and the fourth wall section 33 and the annular collar 54 of the first working piston 32), the piston assembly 16 assumes the second functional position in a defined manner. In this case, it is provided that the actuating element 81 lifts the valve element 17 with its tip 82 from the valve seat 76, so that the fluid passage 72 is released. Liquid which may be present in the first fluid region 40 may flow away in the vertical direction downwards under the influence of gravity alone through the bore 37, the fluid passage 72 and the longitudinal recess 80 in the actuating element 81. Accordingly, it is assumed that the float 18 is in the lowered position according to fig. 3, which is different from the illustration in fig. 1 and corresponds to the illustration in fig. 3, so that the valve element 19 seals the connection opening 47.

When fluid pressure is provided by the compressed air source at the inlet connection 5, liquid which may still be present at least for a short time also flows away downwards in the vertical direction through the bore 37, the fluid channel 72 and the longitudinal recess 80 in the actuating element 81. In addition, as a result of the pressure buildup in the first fluid region 40, the overpressure in the working recess 24 is regulated relative to the second fluid region 56 and the third fluid region 57 which is sealed off at this point in time.

The build-up of the overpressure in the working recess 24 can be established in that, although the fluid channel 72 is not closed off by the valve element 17 at this point in time, the fluid flow through the fluid channel 72 is significantly smaller due to the smaller cross section than the fluid inflow through the bore 37. Correspondingly, the resulting forces directed upward along the center axis 8 according to the illustrations of fig. 1 and 2 result from the different compression forces acting on the piston assembly 16.

In this case, the area ratios of the first working piston 32 and the second working piston 60 in the working recess 24 (Fl ä chenverh ä ltnisse) are adapted to one another in such a way that the resulting force on the piston assembly 16 is also sufficient in the case of an open fluid channel in order to transfer the piston assembly 16 from the second functional position according to fig. 1 into the first functional position according to fig. 2 under elastic deformation of the helical spring 67.

In this case, the valve seat 76 and the actuating element 81 are moved away from one another until the tip 82 of the actuating element 81 no longer penetrates the valve seat 76 and therefore the valve member 17 blocks a further fluid flow through the fluid channel 72. As soon as the piston face 65 of the second working piston 60 abuts against the inner face 69 of the upper part 21, the movement of the piston assembly 16 is ended, as this is represented in fig. 2. This position of the piston assembly 16 corresponds to the first functional position. At this point in time, fluid exiting through the condensate drain valve 2 does not occur at all.

As soon as a fluid flow then occurs from inlet connection 5 to outlet connection 6 and is to be loaded with moisture, moisture separator 7 can at least partially separate the moisture contained in the fluid flow, in particular in the compressed air flow, wherein the separated moisture leaves moisture separator 7 purely exemplarily below and gradually collects as liquid water level 92 in first fluid region 40.

With increasing amount of liquid separated by the moisture separator 7, the liquid level 92 rises, so that the float 18 is flushed around by the liquid. As soon as the liquid level 92 rises to such an extent in the first fluid region 40, the amount of liquid displaced by the float 18 corresponds to the sum of the weight force of the float 18 and the possible friction forces, the float 18 floating and thus leaving the lowered position represented in fig. 3.

With a further rising liquid level, the float 18 executes a linear movement in the vertical direction up to the raised position according to fig. 1, wherein the valve element 19, which is accommodated pivotably movably in the valve well 89, executes a pivoting movement from the horizontal position represented in fig. 3 into the inclined position, as it is represented in fig. 1. In this case, the valve element 19 is lifted off the connection opening 47, so that a fluid-communicating connection is established between the first fluid region 40 and the third fluid region 57.

Thereby, an inflow of pressure-loaded fluid from the first fluid region 40 into the third fluid region 57 is achieved, whereby a pressure build-up occurs in the third fluid region 57. This pressure build-up depends substantially on the cross-section of the connection opening 47 and the throttle 71 and on the pressure conditions in the first fluid region 40 and in the second fluid region 56.

The cross section of the throttle element 71 is preferably selected such that significantly more compressed air can flow into the third fluid region 57 via the connecting opening 47 than can flow away through the throttle element 71. Correspondingly, the pressure in the third fluid region 57 has already been set at least almost to the same pressure as in the first fluid region 40 after a short time.

As soon as the pressure in the third fluid region 57 corresponds at least approximately to the pressure in the first fluid region 40, the resulting force directed downward in the vertical direction results from the compression force acting on the piston assembly 16 taking into account the downward acting spring force of the helical spring 67, as a result of which the piston assembly 16 is transferred from the first functional position according to fig. 2 into the second functional position according to fig. 1.

During this transfer of the piston assembly 16, the valve element 17 is lifted off the valve seat 76 by the tip 82 of the actuating element 81, so that the fluid passage 72 is released and a fluid-communicating connection is established between the first fluid region 40 and the second fluid region 56. Correspondingly, starting from this point in time, a flow of liquid from the first fluid region 40 through the bore 37, the fluid channel 72 and the longitudinal recess 80 of the actuating element 81 is effected. As the liquid flows away, the liquid level 96 drops again, whereby the float 18 leaves the raised position according to fig. 1 and returns again to the lowered position according to fig. 3.

Correspondingly, the connection opening 47 is in turn closed by the valve element 19, which returns to its horizontal position according to fig. 3 in the event of a lowering movement of the float 18. Thus, the connection of fluid communication between the first fluid region 40 and the third fluid region 57 is interrupted and no further fluid inflow into the third fluid region 57 takes place. However, since the fluid flow through the throttle 71 otherwise occurs, a pressure builds up in the third fluid region until the pressure prevailing in the second fluid region 56, the resulting force (which is composed of the compression force on the piston assembly 16 and the spring force of the helical spring 67) acts in the vertical direction upwards on the piston assembly 16 and which moves counter to the spring force of the helical spring 67 from the second functional position according to fig. 1 back into the first functional position according to fig. 2.

Due to the linearly movable mounting of the coupling element 78, manual actuation of the valve element 17 is also possible. In this case, an axial force directed upward in the vertical direction is applied by the user to the coupling element 78, as a result of which the actuating element 81 lifts the valve element 17 with its tip 82 from the valve seat 76 and thus releases the fluid channel 72 for the collected liquid to flow away. The return of the coupling element 78 into the position according to fig. 1 and 2 can be ensured either by gravity or by a return spring which is not represented in greater detail.

Claims (21)

1. A condensate drain valve for a compressed air maintenance device (1), having a valve housing (15), which valve housing (15) is penetrated by a first recess, in which a piston assembly (16) is accommodated in a linearly movable manner along a movement axis (23) between a first functional position and a second functional position, wherein the piston assembly (16) has a first working piston (32), which first working piston (32) bears radially sealingly against the first recess (24), separating a first fluid region (40) from a second fluid region (56), wherein the first working piston (32) is penetrated by a fluid channel (72), which fluid channel (72) extends between the first fluid region (40) and the second fluid region (56) and which fluid channel (72) comprises a valve chamber (75), in which valve chamber (75) a valve seat (76) for the sealing support of a valve member (17) is formed and in which the valve member (17) is accommodated, wherein the movable piston assembly (16) bears sealingly against the second fluid region (60) via a fluid channel (57), wherein the first working piston assembly (16) is connected to the second fluid region (57) via a fluid channel (47), wherein the second working piston assembly (24) is radially movable by the fluid channel (57) and wherein the valve member (57) is connected to the first working piston assembly (24), wherein the second working piston assembly (57) is sealingly bears radially against the fluid channel (57), wherein the fluid channel (47) and wherein the fluid channel (32) and the fluid channel (57) is formed in which fluid channel (47) and the fluid channel (60) and the fluid channel (24) is formed in which fluid channel (57) and the fluid channel (60) is formed between the working piston assembly (24) and the working piston assembly In a connection communicating with the first fluid region (40), with a float (18) which is arranged in the first fluid region (40) and is mounted on the valve housing (15) in a linearly movable manner between a lowered position and a raised position, a valve element (19) being mounted on the float (18), which valve element (19) seals the connection opening (47) in the lowered position and which valve element (19) releases the connection opening (47) in the raised position, wherein the piston assembly (16) is traversed by a connection channel (70,71), which connection channel (70,71) extends between the first fluid region (40) and the second fluid region (56) and wherein an actuating element (81) is mounted on the valve housing (15), which actuating element (81) traverses the fluid channel (72) in the region of the valve seat (76) in the second position of the piston assembly (16) and lifts the valve (17) from the valve seat (76) in the second fluid communication region, so that a fluid connection exists between the second fluid region (40) and the second fluid region (56).

2. A condensate drain valve according to claim 1, characterized in that the cross-section of the connection opening (47) is at least 2 times the cross-section of the connection channel (70,71).

3. A condensate drain valve according to claim 1 or 2, characterized in that between the piston assembly (16) and the valve housing (15) there is arranged a pretensioned spring means (67) which determines one of two functional positions of the piston assembly (16) as a preferred position.

4. A condensate drain valve according to claim 1 or 2, characterized in that the operating element (81) is movably received at the valve housing (15) and/or is configured as a coupling for a fluid line.

5. A condensate drain valve according to claim 1 or 2, characterized in that the valve element (19) is movably mounted at the float (18).

6. The condensate drain valve according to claim 1 or 2, characterized in that the connection opening (47) is configured at an end shield (44) of a sleeve section (43) of the valve housing (15), wherein a movement path of the float (18) between the lowered position and the raised position is oriented parallel with respect to a longitudinal axis (8) of the sleeve section (43).

7. A condensate drain valve according to claim 6, characterized in that the float (18) is at least partly penetrated by a second recess (85), which second recess (85) is configured for accommodating the sleeve section (43) of the valve housing (15) so as to form a linear guide.

8. A condensate drain valve according to claim 6, characterized in that the oscillation axis (91) for the valve element (19) is oriented transversely to the longitudinal axis (8) of the sleeve section (43).

9. A condensate drain valve according to claim 8, characterized in that the distance between the pivot axis (91) of the valve element (19) and the bearing area of the valve element (19) on the connection opening (47) corresponds at least to the distance between the lowered position and the raised position of the float (18).

10. A condensate drain valve according to claim 1 or 2, characterized in that the fluid active surface of the second working piston (60) in the third fluid region (57) is at least 1.5 times the fluid active surface of the first working piston (32) in the first fluid region (40).

11. A condensate drain valve according to claim 2, characterized in that the cross-section of the connection opening (47) is at least 4 times the cross-section of the connection channel (70,71).

12. A condensate drain valve according to claim 11, characterized in that the cross-section of the connection opening (47) is at least 8 times the cross-section of the connection channel (70,71).

13. A condensate drain valve according to claim 3, characterized in that the spring means (67) is a helical spring.

14. A condensate drain valve according to claim 3, characterized in that the spring means (67) determines the second functional position of the piston assembly (16) as a preferred position.

15. A condensate drain valve according to claim 4, wherein the fluid line is a fluid hose.

16. A condensate drain valve according to claim 5, characterized in that the valve element (19) is mounted swingably at the float (18).

17. A condensate drain valve according to claim 6, characterized in that the connection opening (47) is configured at the apex of an end shield (44) of the sleeve section (43) of the valve housing (15).

18. A condensate discharge valve according to claim 6, characterized in that the movement path of the float (18) between the lowered position and the raised position is coaxially oriented with respect to the longitudinal axis (8) of the sleeve section (43).

19. A condensate drain valve according to claim 10, characterized in that the fluid active surface of the second working piston (60) in the third fluid region (57) is at least 2 times the fluid active surface of the first working piston (32) in the first fluid region (40).

20. A condensate drain valve according to claim 19, characterized in that the fluid active surface of the second working piston (60) in the third fluid region (57) is at least 2.5 times the fluid active surface of the first working piston (32) in the first fluid region (40).

21. A maintainer for compressed air production, with a catch vessel (3) for liquid, with a separating device (7) for separating liquid from compressed air flow, and with a condensate drain valve (2) according to one of the preceding claims, wherein a valve housing (15) of the condensate drain valve (2) is sealingly accommodated in a recess (10) on the bottom side of the catch vessel (3) and wherein the first fluid region (40) is bounded by the catch vessel (3).

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