DE102017222731B4 - Filter device for filtering compressed air - Google Patents

Abstract

Filter device for filtering compressed air, with a filter assembly (6) having a main axis (7), which comprises a cup-shaped filter shell (8) and a filter unit (9) having a filter medium (19), the filter unit (9) being axially connected by a frontal shell opening (15) into a position of use in the interior (14) of the filter shell (8) can be inserted or inserted, first and second locking means (22a, 22b) cooperating with one another on the filter unit (9) and on the filter shell (8). locking device (22) are arranged, by means of which the filter unit (9) is locked in its position of use relative to the filter shell (8) in an axially immovable, releasable manner, the first locking means (22a) being arranged via at least one locking element (37 ) which has a locking projection (38) that can be moved in the radial direction with respect to the main axis (7) by manual actuation of the locking element (37), via which it can be used in the locked position of use of the filter unit (9) with the filters arranged on the filter bowl (8). second locking means (22b) is in locking engagement, wherein the filter unit (9) in connection with an actuation of the at least one locking element (37) by a pure linear movement (48) oriented in the axial direction of the main axis (7) both into the usage position and out can be moved out of the position of use relative to the filter bowl (8), the second locking means (22b) on the filter bowl (8) having at least one immovable locking projection (38) which is radially oriented with respect to the main axis (7) and which in the locked position of use of the filter unit (9) is engaged behind by the locking projection (38) of the at least one movable locking element (37) of the first locking means (22a) on an axial end face (34) oriented in the axial direction of the main axis (7), characterized in that the locking projection (38 ) of the at least one locking element (37) protrudes radially inwards towards the main axis (7) and the at least one locking projection (33) of the second locking means (22b) protrudes radially outwards from the main axis (7), the at least one The locking element (37) in the locked position of use of the filter unit (9) extends axially past the locking projection (33) of the second locking means (22b) radially on the outside.

Description

The invention relates to a filter device for filtering compressed air, with a filter assembly having a main axis, which includes a cup-shaped filter shell and a filter unit having a filter medium, the filter unit being insertable or inserted axially through an end shell opening into a usage position in the interior of the filter shell , wherein mutually cooperating first and second locking means of a locking device are arranged on the filter unit and on the filter bowl, by means of which the filter unit is locked in an axially immovable, releasable manner relative to the filter bowl in its position of use, the first locking means having at least one locking element arranged movably on the filter unit , which has a locking projection that can be moved in the radial direction with respect to the main axis by manual actuation of the locking element, via which it is in locking engagement with the second locking means arranged on the filter bowl when the filter unit is in the locked position of use, the filter unit being connected to an actuation of the at least one The locking element can be moved relative to the filter bowl by a pure linear movement oriented in the axial direction of the main axis into the position of use.

One from the DE 10 2018 054 878 A1 Known filter device of this type has a filter unit that can assume a position of use in which it is inserted into a filter shell referred to as a housing bell and is releasably fixed by means of a residual connection. For latching purposes, the filter unit has two radially movable locking elements which can each be detachably latched with a latching lug of the filter shell. The locking can be brought about either by a pure linear movement or by a rotary movement of the filter unit. To release the locking connection, the filter unit can be rotated relative to the filter bowl, whereupon it can be pulled out of the filter bowl in a linear manner.

One from the DE 11 2011 105 227 T5 known filter device has a filter assembly, which is composed of a cup-shaped filter bowl and a filter unit used in its position of use in the filter bowl. The filter unit has a filter medium through which compressed air flows when the filter device is used in order to filter out impurities from the compressed air. The filter assembly can be handled in a unitary manner, which simplifies assembly and disassembly with respect to a main body to which the filter assembly is detachably attached when in use. To fix the filter unit to the filter bowl, there is a locking device which has locking means arranged on the filter unit and on the filter bowl, which can be selectively engaged and disengaged by rotating the filter unit with respect to the filter bowl. When the locking means are engaged with one another in the locked use position of the filter unit, the filter unit is releasably locked axially immovably relative to the filter bowl.

The DE 10 2008 054 878 A1 discloses a compressed air filter and a filter element for separating foreign matter from a compressed air flow, with an element base, an element head, which has a neck section forming a first flow channel, and a collar section, which runs around the neck section at least in sections and is connected to the neck section to form a second flow channel and a filter medium which is sealingly connected to the element base and the element head to form a gas flow path between the first flow channel and the second flow channel through the filter medium, wherein the collar section has a contact surface which is provided at least in sections on the outer circumference and tapers in the direction of the element base Receiving an associated sealing ring in such a way that a force acting approximately axially from the direction of the element base on the sealing ring causes a radial expansion of the sealing ring along the contact surface.

The DE 11 2015 001 643 T5 discloses a filter which is retained in a shell housing using a snap fit connection. The filter includes an end plate having latching means which interact with a groove in an interior portion of the shell. The groove may extend 360 degrees around an inner circumference of the shell. Similarly, when the shroud housing is unbolted from the head for maintenance (e.g., during a filter change service), the shroud need only be displaced by the length of the inner radial seal interface between the shroud and head, and not the entire length of the filter media, thereby minimizing the stroke length needed to service the filter assembly.

The invention is based on the object of creating a filter device in which the handling of the filter unit and the filter bowl when locking and unlocking one another is simplified.

This object is achieved with the features specified in claim 1, wherein the filter unit in connection with an actuation of the at least one locking element by a in the axial direction of the main axis oriented pure linear movement is also movable from the position of use relative to the filter bowl.

The filter assembly comprises a cup-shaped filter bowl and a filter unit having a filter medium used for filtering compressed air. In its position of use, the filter unit is inserted into the interior of the filter shell through a shell opening at the front, which during use generally points vertically upwards, in order to assume its position of use. In the position of use, the filter unit can be locked or locked with respect to the filter shell in such a way that the two components are coupled to one another in an axially immovable manner in a manner that can be released at any time. It is advantageous that a relative rotational movement between the two components of the filter assembly does not have to be carried out either for the locking process or for the unlocking process. Both the bringing into the locked position of use and the removal from the locked position of use can be carried out by means of a purely axial linear movement of the filter unit. The main reason for this is the design of the first locking means arranged on the filter unit, which have at least one locking element arranged movably on the filter unit, which has a locking projection which can be moved radially to the main axis by manual actuation of the locking element. In the course of this radial movement of the locking projection, the first locking means are able to pass the second locking means arranged on the filter bowl when locking and unlocking, without a relative rotary movement between the filter unit and the filter bowl being required. Unlocking can expediently be carried out by direct manual actuation of the at least one locking element. The same handling option is expediently also available for the locking process, although it is advantageous if the locking means are coordinated in such a way that locking can be carried out by means of a latching process, which can also be referred to as a snapping process, in which the movement of the locking element is based on the fact that it occurs when it is inserted of the filter unit slides into the filter bowl at the second locking means and is thereby caused to the mentioned radial movement.

The first locking means are preferably equipped with two locking elements which are diametrically opposite one another with respect to the main axis of the filter assembly and can be actuated independently of one another. This ensures a secure axial locking in connection with a simple one-hand unlocking by simultaneous manual actuation of the two locking elements with the thumb and another finger of one hand.

The locking elements could be designed, for example, as locking slides that can be displaced transversely to the main axis. However, a design is considered to be particularly advantageous in which each locking element of the first locking means is hook-shaped and can be pivoted radially with respect to the main axis of the filter assembly.

Each hook-shaped locking element expediently contains an actuating section which is spaced apart from the associated locking projection and which, in particular for unlocking, enables a direct manual introduction of an actuating force.

The hook-shaped locking element is preferably suspended on the filter unit so that it can pivot in a rocker-like manner, with the locking projection and the actuating section being located on opposite sides of a pivot bearing area. The actuation section can be acted upon with a finger and in particular moved in the radial direction with respect to the main axis, resulting in an opposite radial deflection of the locking projection arranged on the same locking element.

Preferably, the locking element is resiliently suspended on the filter unit, so that when the actuating force causing the deflection is removed, it automatically pivots back into a non-deflected initial position. In this context, it is advantageous if the pivot bearing area is formed by at least one elastically deformable material web of the filter unit. There is the advantageous possibility of designing the locking element, for example, in the form of a strap and suspending it in a spring-elastically pivotable manner on mutually opposite edge regions, each with an elastically deformable material web.

According to the invention, the second locking means arranged on the filter bowl contain at least one immovable locking projection which is oriented radially with respect to the main axis and which, when the filter unit is in the locked position of use, is engaged behind by the locking projection of the at least one movable locking element of the first locking means on an axial end face oriented in the axial direction of the main axis. The movable locking element preferably extends radially past the locking projection in the axial direction of the main axis and extends with the locking development projection in the radial direction in one of the axial end face of the locking projection axially adjacent area.

Furthermore, the invention provides that the locking projection of the at least one locking element is oriented radially inwards towards the main axis, while the at least one locking projection of the second locking means projects radially outwards from the main axis in the opposite direction. In the locked position of use of the filter unit, the locking element extends radially outward past the locking projection of the second locking means.

The second locking means preferably have an annular locking projection coaxial to the main axis of the filter assembly, with which in the locked position of use of the filter unit each locking element of the first locking means is in locking engagement with its locking projection. This makes it particularly easy to implement a locking device that allows the latching process to be carried out in any desired relative rotational position between the filter unit and the filter bowl. The ring-shaped locking projection is preferably ring-shaped and self-contained.

The annular locking projection of the second locking means expediently delimits on one axial side an annular groove coaxial to the main axis, in which each locking element of the first locking means engages with its locking projection in the locked position of use of the filter unit.

As already mentioned, it is advantageous if the filter unit can be moved into and out of the use position in any desired rotational position relative to the filter bowl with respect to the main axis by means of a purely linear movement oriented in the axial direction of the main axis. In this way, no special rotational angle alignment is required between the filter unit and the filter bowl in order to effect locking or unlocking. The locking measure in particular is greatly simplified as a result and can be carried out in a short amount of time.

In its locked position of use, the filter unit can expediently be rotated about its main axis relative to the filter bowl while maintaining the locked position of use. During this relative rotational movement, the first locking means slide along the second locking means in the circumferential direction of the main axis without losing the locking engagement. This measure can be implemented very advantageously in particular in connection with an embodiment in which the second locking means have an annular locking projection provided for interaction with each locking element of the first locking means, as already mentioned above.

It is advantageous if the at least one locking element of the first locking means is arranged on the filter unit in a resiliently flexible manner in such a way that when the filter unit is linearly inserted into the filter bowl it can be temporarily deflected by contact with the second locking means and without direct manual actuation of the second locking means can be brought into a locking engagement. In this context, the locking element is expediently provided with a loading surface inclined with respect to the main axis, with which it can slide off the second locking means with simultaneous radial deflection when the filter unit is inserted into the filter bowl.

In this way, no direct manual actuation of the at least one locking element is required in order to lock the filter unit to the filter bowl. It is sufficient to push the filter unit through the front shell opening into the filter shell with a certain amount of force, so that due to the manual actuating force applied, the at least one locking element snaps into the second locking means and in this respect enters into a releasable snap-in lock.

The first locking means are expediently arranged on an axial end section of the filter unit which is associated with the filter unit in the position of use of the shell opening of the filter shell.

The filter unit preferably has a centering ring delimiting an axially open centering recess, into which the filter shell, when the filter unit is in the position of use, dips with an axial end section which encloses the shell opening and has the second locking means.

This results in a coaxial centering of the filter unit with respect to the filter bowl. The at least one locking element is expediently integrated into this centering ring of the filter unit. It can be formed by a longitudinal section of the centering ring that can be moved in particular in a resilient manner. The centering ring can be segmented, with each locking element in the circumferential direction of the main axis is incorporated between two consecutive ring segments of the centering ring.

In addition to the filter medium, the filter unit expediently contains a separate filter medium carrier in this regard. The filter medium support has two support bodies which are detachably joined together axially to incorporate the filter medium, one of which forms a fastening section of the filter unit which has the first locking means and via which the filter unit is fastened to the filter shell in the locked position of use. The filter means is preferably designed in the form of a sleeve and preferably in the form of a hollow cylinder. The filter means is designed in particular as a filter cartridge. If the filter medium is dirty, it can easily be replaced by temporarily disassembling the filter medium carrier.

Preferably, the filter device includes a main body having an underside to which the filter assembly is releasably mounted in its operative position with an axial upper side having the bowl opening first. The main body is traversed by an inlet duct and an outlet duct, these two ducts opening out at one end on the underside of the main body so as to be in fluid communication with the interior of the filter assembly when in use. Both channels also have connection openings that are accessible from the outside in order to be able to supply and discharge the compressed air to be filtered.

The filter assembly is releasably mountable or mounted in an operative position on the main body, for example by means of a bayonet connection device.

The filter device is preferably designed as a so-called maintenance device that is used for compressed air treatment. The filter device is preferably designed in such a way that it can be used as one of several maintenance devices for realizing a modular maintenance unit.

• 1 eine bevorzugte Ausführungsform der erfindungsgemäßen Filtervorrichtung in einer perspektivischen Darstellung,
• 2 die Filtervorrichtung aus 1 in einem Längsschnitt gemäß Schnittlinie II-II aus 1,
• 3 einen Querschnitt der Filtervorrichtung gemäß Schnittlinie III-III aus 2 und 4, wobei die Komponenten des in 2 ersichtlichen Hauptkörpers der Filtervorrichtung nicht gezeigt sind,
• 4 einen Längsschnitt der bei der Filtervorrichtung der 1 und 2 vorhandenen Filterbaugruppe gemäß Schnittlinie IV-IV aus 3, wobei in einem strichpunktiert umrahmten Ausschnitt ein vergrößertes Detail gezeigt ist,
• 5 einen weiteren Längsschnitt der Filterbaugruppe in einer bezüglich 4 abweichenden Schnittebene gemäß Schnittlinie V-V aus 3, wobei in einem strichpunktiert umrahmten Ausschnitt ein Zustand während des axialen Einsteckens der Filtereinheit in die Filterschale gezeigt ist und wobei in einem weiteren strichpunktiert umrahmten Ausschnitt ein vergrößertes Detail gezeigt ist,
• 6 einen Längsschnitt der Filterbaugruppe analog des Längsschnittes der 5, jedoch in einer isometrischen Darstellung,
• 7 einen weiteren isometrischen Längsschnitt der Filterbaugruppe, wobei nur ein Viertel der Umfangserstreckung der Filterbaugruppe gezeigt ist,
• 8 eine Explosionsdarstellung der Filtervorrichtung, wobei ein Hauptkörper, die Filtereinheit und die Filterschale einzeln sichtbar sind und wobei die Filtereinheit für sich gesehen auch nochmals separat in einer Explosionsdarstellung illustriert ist, und
• 9 einen Längsschnitt der Filtereinheit gemäß Schnittlinie IX-IX aus 8 in wiederum einer Explosionsdarstellung.

The invention is explained in more detail below with reference to the attached drawing. In this show:

• 1 a preferred embodiment of the filter device according to the invention in a perspective view,
• 2 the filter device 1 in a longitudinal section according to section line II-II 1 ,
• 3 a cross section of the filter device according to section line III-III 2 and 4 , where the components of the in 2 visible main body of the filter device are not shown,
• 4 a longitudinal section of the in the filter device 1 and 2 existing filter assembly according to section line IV-IV 3 , whereby an enlarged detail is shown in a section framed by dot-dashed lines,
• 5 a further longitudinal section of the filter assembly in a respect 4 deviating section plane according to section line VV 3 , wherein a detail framed by dash-dotted lines shows a state during the axial insertion of the filter unit into the filter bowl and wherein an enlarged detail is shown in a further detail framed by dash-dotted lines,
• 6 a longitudinal section of the filter assembly analogous to the longitudinal section of 5 , but in an isometric representation,
• 7 another isometric longitudinal section of the filter assembly, with only a quarter of the circumferential extent of the filter assembly being shown,
• 8th an exploded view of the filter device, wherein a main body, the filter unit and the filter bowl are individually visible and wherein the filter unit is also illustrated separately in an exploded view, and
• 9 a longitudinal section of the filter unit according to section line IX-IX 8th again in an exploded view.

The filter device denoted in its entirety by reference number 1 can be used for filtering compressed air in order to filter out impurities contained in the compressed air.

The filter device 1 preferably has a block-shaped main body 2, for example, on whose outer surface an inlet opening 3a for feeding compressed air to be filtered and an outlet opening 4a for the discharge of the filtered compressed air are arranged. A filter assembly 6 is detachably mounted on an underside 5 of the main body 2 which points vertically downwards in the usual position of use, assuming its operating position. The filter assembly 6 has an imaginary main axis 7 which at the same time defines a main axis of the entire filter device 1 .

The filter assembly 6 comprises a cup-like filter bowl 8 and a filter unit 9 which is accommodated at least partially and preferably entirely in the filter bowl 8 when it is in its position of use.

The filter assembly 6 has an axially oriented top surface 12 which advances it in operation position on the underside 5 of the main body 2 is attached. The filter assembly 6 is detachably fastened to the main body 2 with the aid of a fastening device 13 whose components are arranged partly on the filter assembly 6 and partly on the main body 2 . The fastening device 13 is preferably designed as a bayonet connection device, so that assembly takes place by means of a plug-and-turn movement and disassembly by means of a rotary movement and subsequent axial withdrawal movement.

The filter assembly 6 has a shell interior 14 which is delimited by the filter shell 8 and into which the filter unit 9 protrudes. In the area of the upper side 12 the filter shell 8 has an axially oriented shell opening 15 which defines the access to the shell interior 14 and through which the filter unit 9 is introduced into the shell interior 14 . The filter unit 9 is at least partially hollow and defines a filter unit interior 16 which is accessible on an axial end face through an interior opening 17 located there. The latter is oriented in the same way as the shell opening 15 of the shell interior 14 and is preferably at the same height with respect to the axial direction of the main axis 7 .

In the following, the axis direction of the main axis 7 is simply referred to as the main axis direction or as the axial direction.

The inlet opening 3a belongs to an inlet channel 3, which passes through the main body 2 and opens out on the underside 5 with an inflow opening 3b. The outlet opening 4a belongs to an outlet channel 4 which also passes through the main body 2 and which opens out on the underside 5 with an outflow opening 4b. In the mounted operating position of the filter assembly 6, the inflow opening 3b communicates with the interior space 14 of the shell via the shell opening 15, and the outflow opening 4b communicates with the interior space 16 of the filter unit via the interior opening 17.

During operation of the filter device 1, compressed air is fed in via the inlet opening 3a, which flows through the inlet channel 3 into the interior space 14 of the shell. From there, the compressed air passes through an air-permeable and at the same time filtering filter wall 18 of a filter medium 19 of the filter unit 9 into the filter unit interior 16, from where it flows through the interior opening 17 into the outlet channel 4, which it passes through the outlet opening 4a to be supplied to a consumer device, for example a drive device operated with compressed air.

When it flows through the filter wall 18 , which consists, for example, of fiber material or sintered material, impurities in the compressed air are filtered out, so that the compressed air flowing out at the outlet opening 4a has a high degree of purity.

When in use, the filter device 1 is expediently fastened via its main body 2 to a supporting structure that is not illustrated in any more detail.

The components of the fastening device 13 belonging to the filter assembly 6 are expediently arranged only on the filter shell 8 and not on the filter unit 9 . They consist, for example, of a plurality of bayonet connection projections 13a that protrude radially with respect to the main axis 7 .

Even when the filter assembly 6 is not mounted on the main body 2, the filter unit 9 and the filter bowl 8 can be assembled into a unit that can be handled uniformly and is fixed to one another in an axially immovable manner. Here, the filter unit 9 assumes the position of use inserted into the shell interior 14 of the filter shell 8 , which is a locked position of use in which the filter unit 9 is axially immovably releasably locked relative to the filter shell 8 . Responsible for this releasable locking is a locking device 22 which is composed of first locking means 22a arranged on the filter unit 9 and second locking means 22b arranged on the filter bowl 8 .

The use position of the filter unit 9, which is responsible for the uniform handling of the filter assembly 6 and is locked with respect to the filter bowl 8, is, for example, in FIGS 4 and 5 until 7 apparent. In the 5 only the left half of the image shows the locked position of use, while the detail illustrated in the right half of the image shows a phase in the assembly of the filter unit 9 and the filter bowl 8 in which the locking means 22a, 22b are not yet in an axially blocking locking engagement with one another.

The bowl interior 14 is closed fluid-tight all around by the filter bowl 8 . On an underside 23 axially opposite the top 12, the filter shell 8 expediently has a condensate drain device 24, through which condensate that has accumulated in the shell interior 14 can be drained off automatically or as needed. The condensate drain device 24 is preferably inserted into a gas-tight shell body 25 of the filter shell 8 .

The filter unit 9 has a fastening section 26 which is preferably located on that axial end section of the filter unit 9 on which the axially oriented interior opening 17 is also arranged. When the filter unit 9 is in the mounted position of use, the fastening section 26 is preferably at least essentially at the same axial height as the shell opening 15 and at least partially dips into the shell interior 14 .

The fastening section 26 is expediently the only component of the filter unit 9 via which the filter unit 9 is fixed to the filter shell 8 in the locked position of use. Starting from there, the filter unit 9 protrudes into the shell interior 14 in a self-supporting manner and freely ending at its end section facing the underside 23 .

The fastening section 26 expediently defines an axially continuous annular flow gap 27 through which the compressed air can flow from the inlet channel 3 into the shell interior 14 . The flow gap 27 is expediently associated with swirl generating means 28 which ensure that the compressed air flowing through experiences a swirl, which is advantageous for the air distribution in the shell interior 14 .

The fastening section 26 is therefore expediently equipped with a swirl-generating device for the compressed air.

The first locking means 22a are expediently designed as integral components of the fastening section 26 . The second locking means 22b are expediently located on the shell body 25, which consists in particular of glass or a plastic material.

The second locking means 22b are expediently formed on the axial end section of the filter bowl 8 facing the upper side 12, which is also referred to below as the upper end section 32 of the filter bowl 8 for the sake of simplicity.

The second locking means 22b belonging to the filter bowl 8 contain at least one locking projection 33 designed for locking interaction with the first locking means 22a. Preferably and according to the illustrated embodiment, this is an annular locking projection 33 coaxial with the main axis 7. This annular locking projection 33 protrudes radially outwards in relation to the main axis 7, comparable to an annular collar, and has a lower axial end surface 34 facing the underside 23, which is also referred to below as the locking surface 34 for better differentiation. This axial end face 34 is in particular an annular face.

The annular locking projection 33 expediently delimits an annular groove 35 which is introduced into the outer circumference of the upper end section 32 of the filter bowl 8 and which is aligned coaxially with the main axis 7 . The annular locking projection 33 adjoins the annular groove 35 towards the upper side 12 , which is thus located axially below the locking projection 33 .

Advantageously, this annular groove 35 is followed at an axial distance in the direction of the underside 23 by an annular seal-receiving groove 36, in which a sealing ring 36a is received, which in the installed operating position of the filter assembly 6 bears against the main body 2 with a seal, in order to enclose the channels 3 , 4 and to seal the interior of the filter assembly 6 from the environment.

The annular locking projection 33 is arranged immovably on the filter unit 9 and is preferably rigid.

The first locking means 22a of the locking device 22 contain at least one locking element 37 arranged movably on the filter unit 9. The first locking means 22a preferably contain a plurality of movable locking elements 37 arranged in a preferably uniform distribution around the main axis 7 on the filter unit 9. It is particularly advantageous viewed when exactly two locking elements 37 are present, which are arranged in relation to the main axis 7 diametrically opposite locations on the attachment portion 26 of the filter unit 9. This applies to the embodiment.

The locking elements 37 can be actuated independently of one another and each have a locking projection 38 which, when the associated locking element 37 is actuated, executes a working movement 42 which is oriented radially with respect to the main axis 7 and is illustrated by a double arrow. Depending on the direction of movement, this involves an unlocking movement 42a, indicated in the drawing by an arrow, or an opposite locking movement, which is not illustrated further. The first locking means 22a are designed in particular in such a way that the unlocking movement 42a is directed radially away from the main axis 7 . This applies to the embodiment.

Each locking element 37 is expediently hook-shaped and suspended on the filter unit 9 so that it can pivot like a rocker. The arrangement is such that the pivot axis preferably lies in a plane at right angles to the main axis 7 . The pivot axis is defined by a pivot bearing area 43, which is preferably formed by at least one elastically deformable material web 44.

By way of example, each locking element 37 is arranged on the peripheral outer circumference of the fastening section 26 and extends a little in the circumferential direction of the main axis 7 , that is to say around the main axis 7 . Each locking element 37 is fixed at its mutually opposite end regions in relation to the circumferential direction of the main axis 7 via an elastically deformable material web on a rigid base section 55 of the fastening section 26 . This is particularly clear from the figure on the right 8th to see.

The locking element 37 projects away from the pivot bearing area 43 in opposite directions transversely to the pivot axis defined thereby. On one side of the pivot bearing area 43, the locking element 37 has the locking projection 38, on the opposite side has an actuating section 45 that can be actuated manually. The actuating section 45 is thus spaced apart from the locking projection 38, with two lever arms being formed, one of which consists of the the portion extending between the pivot support portion 43 and the operating portion 45 and the other of the portion extending between the pivot support portion 43 and the locking projection 38 .

The locking projection 38 is arranged on the locking element 37 preferably pointing radially inwards in the direction of the main axis 7 . In the locked position of use, the locking element 37 with the locking projection 38 dips into the annular groove 35 from radially outside and thereby engages behind the locking surface 34 oriented axially downwards on its underside. Consequently, the filter unit 9 is positively secured against being pulled out of the filter bowl 8 axially.

The axial insertion depth of the filter unit 9 with respect to the filter bowl 8 in the position of use is specified in particular by a stop shoulder 46 of the fastening section 26 which, for example, is supported on the upper end face of the upper end section 32 of the filter bowl 8 .

Thus, in the locked position of use, the filter unit 9 is fixed in a form-fitting manner so that it cannot move in relation to the filter bowl 8 in both axial directions of the main axis 7 .

By manually applying an actuating force FB to the actuating section 45, the locking element 37 can be pivoted out of an unactuated starting position, with the locking projection 38 performing the unlocking movement 42a. If the locked position of use of the filter unit 9 is present in the non-actuated initial position, this leads to unlocking of the locking device 22 , which offers the possibility of pulling the filter unit 9 out of the filter bowl 8 axially.

Each locking element 37 is expediently arranged on the filter unit 9 in a resilient manner in such a way that it assumes a locking position in the non-actuated initial position when the filter unit 9 is inserted into the filter bowl 8 . There is a locking engagement between the locking projection 38 and the second locking means 22b.

When the locking element 37 is actuated manually, the resulting unlocking movement 42a leads to the build-up of a resilient restoring force, which means that the locking element 37 automatically pivots back into the locking position when the actuating force is removed from the locking element 37 again.

To assemble the filter assembly, the filter unit 9 is inserted into the filter bowl 8 through the bowl opening 15 with its underside opposite the mounting portion 26 first. The first locking means 22a approach according to the detail view of FIG 5 to the second locking means 22b of the filter bowl 8. In order to effect the locking, the existing locking elements 37 can be shifted outwards from their initial position into an unlocking position by direct manual application of an actuating force FB to the actuating sections 45, so that it is possible for them to attach the filter unit 9 when the filter unit 9 is pushed in according to arrow 47 to reach past the exemplary annular locking projection 33 and to reach the same axial height as the annular groove 35 . If the actuating force FB is now removed, the locking elements 37 pivot back to their initial position, which is now the locking position in which they are in axial locking engagement with the second locking means 22b.

Conversely, the filter unit 9 can also be removed from the filter bowl 8 again at any time when the filter assembly 6 has been removed from the main body 2 . The filter unit 9 can be grasped, for example, with the thumb and another finger of one hand on the actuating sections 45 of the two locking elements 37 and the actuating sections 45 can be pressed together so that the locking elements 37 are pivoted from the locked position into the unlocked position, whereupon the unlocked filter unit 9 moves very much can simply be pulled out of the filter bowl 8.

The illustrated exemplary embodiment offers the additional advantage that the direct manual actuation of the locking elements 37 caused by the actuation of the actuation sections 45 described above can be omitted when the filter unit 9 is inserted into the filter bowl 8, if required. During the linear movement 48 taking place in the sense of the insertion 47, each locking element 37 hits the second locking means 22b, in particular the annular locking projection 33, with an application surface 52 formed in particular on its downward-pointing end face, and is thereby pressed radially outwards. It is therefore only necessary to exert a manual insertion force on the filter unit 9 in order to move the locking elements 37 from the initial position into the unlocked position. As it is pushed in further, the locking projection 38 slides radially outwards over the annular locking projection 33 and then automatically snaps into the locking position in the annular groove 35 due to the resilient restoring force.

The locking device 22 makes it possible to move the filter unit 8 in connection with an actuation of each locking element 37 by a pure linear movement 48 oriented in the direction of the main axis, which is indicated by a double arrow, both into the position of use and out of the position of use. In particular, no additional rotary movement of the filter unit 9 relative to the filter bowl 8 is required.

This is promoted by the fact that all locking elements 37 are jointly assigned an annular locking projection 33 of the second locking means 22b. The filter unit 9 can thus be moved in any rotary position assumed relative to the filter bowl 8 by a purely linear movement 48 both into the position of use and out of the position of use. It is irrelevant for the locking effect and also for the unlocking effect with which peripheral section of the annular locking projection 33 the locking projection 38 of the at least one locking element 37 cooperates.

In this respect, no guiding and/or positioning measures are required to ensure that the filter unit 9 can only be inserted into the filter bowl 8 or pulled out of the filter bowl 8 in one or more very specific rotational angle positions assumed with respect to the filter bowl 8 . This allows the filter assembly 6 to be manufactured at low cost.

The locking device 22 is designed in particular in such a way that the filter unit 9 can be freely rotated in its locked position of use while maintaining this locked position of use relative to the filter bowl 8 about the main axis 7, with the first locking means 22a sliding along the second locking means 22b. The filter unit 9 can be pulled out of the filter bowl 8 from any rotary angle position in connection with a direct manual actuation of the locking elements 37 caused by the application of the actuation force FB by a pure linear movement 48 .

According to an exemplary embodiment that is not illustrated, it is possible to assign each locking element 37 its own locking projection 33 on the filter bowl 8 instead of an annular locking projection 33 assigned jointly to all locking elements 37 .

The fastening section 26 of the filter unit 9 expediently has on its radial outer circumference a centering ring 53 which is in particular formed in one piece and which defines a centering recess 54 which is open axially in the direction of the underside of the filter unit 9 . The centering ring 53 is arranged coaxially with the main axis 7 . It expediently has an L-shaped cross section, with a first L-leg 53a being formed onto the base section 55 of the fastening section 26 and with its other second L-leg 53b protruding downward at a radial distance from the base section 55 . The centering recess 54 is thus delimited axially on the inside by the outer circumference of the base section 55 and axially on the outside by the inner circumference of the downwardly projecting second leg 53a of the L.

The radial width of the centering recess 54 is adapted to the width of the upper end section 32 of the filter shell 8, so that the latter fits into the centering recess 54 from below when the filter unit 9 is in the locked position of use dives, whereby the filter unit 9 and the filter bowl 8 are aligned exactly coaxially with one another. The centering effect can be further promoted by providing the centering recess 54 with a cross-sectional contour that tapers axially inward, which applies to the exemplary embodiment.

The at least one locking element 37 of the first locking means 22a is expediently integrated into the centering ring 53 in one piece. The integration takes place in particular in such a way that the locking element 37 is integrated into the circumferential profile of the centering ring 53 and in particular forms a section of the second L-leg 53b of the centering ring 53 protruding downward. The first L-leg 53a used for connection to the base section 55 is expediently omitted in the area of a respective locking element 37 in order not to impede its pivoting movement.

The spring-elastic webs of material 44 expediently each produce an elastic one-piece connection between a pivotable locking element 37 and the rigid section of the centering ring 53 adjoining it in the circumferential direction of the main axis 7 .

especially the 8th and 9 illustrate a preferred multi-part structure of the filter unit 9. Here, the filter unit 9 contains on the one hand the already mentioned filter medium 19 and on the other hand a separate multi-part filter medium carrier 56 in this regard, which is composed of two detachably axially joined first and second carrier bodies 56a, 56b and which contains the filter medium 19 wears.

The at least one movable locking element 37 is preferably integrated into the filter medium carrier 56 in one piece.

The first carrier body 56a forms the fastening section 26 of the filter unit 9. It is preferably designed essentially in the form of a sleeve and has on its inner circumference a first coupling section 57a designed in particular as an internal thread.

The second carrier body 56b has on its underside an annular or disk-shaped support section 58, from which a connecting section 59 protrudes axially upwards, which at its upper end in the region of the outer circumference has a second coupling section 57b formed, for example, by an external thread.

The filter means 19 is sleeve-shaped and in particular hollow-cylindrical and is placed on the connecting section 59 of the second support body 56b, with its lower axial end being supported on the support section 58 . The connecting section 59 extends coaxially through the sleeve-shaped filter means 19 and is fastened with its second coupling section 57b to the first coupling section 57a of the first carrier body 56a. The filter means 19 is integrated between the two carrier bodies 56a, 56b and is braced axially immovably between these two carrier bodies 56a, 56b in that, as mentioned, it is supported on the one hand at the bottom on the support section 58 and on the other hand on the top on the first carrier body 56a.

With this construction, if the filter medium 19 is dirty, it can be easily replaced by dismantling the filter medium carrier 56 of the filter unit 9 previously removed from the filter bowl 8 .

Claims (14)

Filter device for filtering compressed air, with a filter assembly (6) having a main axis (7), which comprises a cup-shaped filter shell (8) and a filter unit (9) having a filter medium (19), the filter unit (9) being axially connected by a frontal shell opening (15) into a position of use in the interior (14) of the filter shell (8) can be inserted or inserted, first and second locking means (22a, 22b) cooperating with one another on the filter unit (9) and on the filter shell (8). locking device (22) are arranged, by means of which the filter unit (9) is locked in its position of use relative to the filter shell (8) in an axially immovable, releasable manner, the first locking means (22a) being arranged via at least one locking element (37 ) which has a locking projection (38) that can be moved in the radial direction with respect to the main axis (7) by manual actuation of the locking element (37), via which it can be used in the locked position of use of the filter unit (9) with the filters arranged on the filter bowl (8). second locking means (22b) is in locking engagement, wherein the filter unit (9) in connection with an actuation of the at least one locking element (37) by a pure linear movement (48) oriented in the axial direction of the main axis (7) both into the usage position and out out of the position of use relative to the filter bowl (8), the second locking means (22b) on the filter bowl (8) having at least one immovable locking projection (38) which is radially oriented with respect to the main axis (7) and which in the locked position of use of the filter unit (9) from the locking projection (38) of the at least one movable locking element (37) of the first locking means (22a) on an axial end face (34) oriented in the axial direction of the main axis (7), characterized in that the locking projection (38) of the at least one locking element (37) extends radially inwards in towards the main axis (7) and the at least one locking projection (33) of the second locking means (22b) projects radially outwards from the main axis (7), the at least one locking element (37) in the locked position of use of the filter unit (9 ) extends axially past the locking projection (33) of the second locking means (22b) radially on the outside. filter device claim 1 , characterized in that the first locking means (22a) have two locking elements (37) which are diametrically opposite one another with respect to the main axis (7) and can be actuated independently of one another. filter device claim 1 or 2 , characterized in that each locking element (37) of the first locking means (22a) is hook-shaped and is designed to be radially pivotable with respect to the main axis (7). filter device claim 3 , characterized in that each hook-shaped locking element (37) has an actuating section (45) spaced apart from its locking projection (38) for the direct manual introduction of an actuating force (FB). filter device claim 4 , characterized in that each hook-shaped locking element (37) is attached to the filter unit (9) so that it can pivot like a rocker, the locking projection (38) and the actuating section (45) being located on opposite sides of a pivot bearing area (43) of the locking element (37). , wherein the pivot bearing area (43) is expediently formed by at least one resiliently deformable material web (44) of the filter unit (9). Filter device according to one of Claims 1 until 5 , characterized in that the second locking means (22b) have an annular locking projection (33) coaxial with the main axis (7), with which, in the locked position of use of the filter unit (9), the locking projection (38) of each locking element (37) of the first Locking means (22a) is in locking engagement. filter device claim 6 , characterized in that the annular locking projection (33) of the second locking means (22b) axially delimits an annular groove (35) into which, in the locked position of use of the filter unit (9), the locking projection (38) of each locking element (37) of the first locking means ( 22a) intervenes. Filter device according to one of Claims 1 until 7 , characterized in that the filter unit (9) in any desired rotational position assumed relative to the filter bowl (8) with respect to the main axis (7) by a pure linear movement (48) oriented in the axial direction of the main axis (7) into the position of use and out the position of use can be moved out. Filter device according to one of Claims 1 until 8th , characterized in that the filter unit (9) in its locked position of use while maintaining the locked position of use can be rotated relative to the filter bowl (8) about the main axis (7), the first locking means (22a) sliding along the second locking means (22b). . Filter device according to one of Claims 1 until 9 , characterized in that the at least one locking element (37) of the first locking means (22a) is arranged on the filter unit (9) in a resiliently flexible manner in such a way that when the filter unit (9) is linearly inserted into the filter bowl (8) it is released by contact with the second locking means (22b) can be temporarily deflected and brought into locking engagement with the second locking means (22b) without direct manual actuation, it expediently having a loading surface (52) inclined with respect to the main axis (7), with which it can be used during the insertion movement can slide with simultaneous deflection on the second locking means (22b). Filter device according to one of Claims 1 until 10 , characterized in that the first locking means (22a) are arranged on an axial end section (32) of the filter unit (9) associated with the shell opening (15) of the filter shell (8) in the position of use. Filter device according to one of Claims 1 until 11 , characterized in that the at least one locking element (37) of the first locking means (22a) is integrated into a centering ring (53) of the filter unit (9), which delimits an axially open centering recess (54) into which the filter bowl (8) fits the position of use of the filter unit (9) with an axial end section (32) surrounding the shell opening (15) and having the second locking means (22b). Filter device according to one of Claims 1 until 12 , characterized in that the filter unit (9), in addition to the filter medium (19), has a separate filter medium carrier (56) in this regard, the filter medium carrier (56) having two carrier bodies (56a, 56b) which are detachably axially joined together with the incorporation of the filter medium (19). , one of which forms a fastening section (26) of the filter unit (9) which has the first locking means (22a) and via which the filter unit (9) is fastened to the filter shell (8) in the locked position of use. Filter device according to one of Claims 1 until 13 , characterized in that it has a main body (2) on which on a lower side (5) the filter assembly (6) can be releasably mounted or is mounted with an axial upper side (12) having the shell opening (15) in front and which is carried by a inlet duct (3) and traversed by an outlet duct (4) for compressed air, both of which open out at the bottom (5) of the main body (2) so as to be in fluid communication with the interior of the filter assembly (6) mounted on the main body (2). .

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