WO2012130379A1

WO2012130379A1 - Fluid-actuated diaphragm drive

Info

Publication number: WO2012130379A1
Application number: PCT/EP2012/001023
Authority: WO
Inventors: Kurt Stoll; Ulrich Kees; Harald Röhrig
Original assignee: Festo Ag & Co. Kg
Priority date: 2011-03-31
Filing date: 2012-03-08
Publication date: 2012-10-04
Also published as: EP2691658B1; CN103443477B; DE102011015646A1; EP2691658A1; CN103443477A

Abstract

Proposed is a fluid-actuated diaphragm drive (1) which has two dome-shaped housing parts (5, 6) which are mounted on one another with two openings, which face towards one another, arranged coaxially. The two housing parts (5, 6) are fixed to one another, at their side surfaces (5b, 6b) which adjoin one another, by means of a bayonet connection device (45). The two housing parts (5, 6) are designed such that the locking projections (46a, 46b) of the bayonet connection device (45) are covered so as not to be visible from the outside.

Description

Fluid operated diaphragm drive

The invention relates to a fluid-actuated diaphragm drive, having a housing having a longitudinal axis, each having one of two in the axial direction of the longitudinal axis by far opposite end-side end walls forming hood-shaped housing parts, each having a framed by an annular side wall opening and the common Limiting a housing interior with mutually facing openings coaxially attached to each other and in the region of the annular side walls by an engaging from behind locking projections of the

Housing parts formed bayonet connection means are fastened together, and comprising a drive unit comprising a fixed between the two housing parts and axially deflectable membrane which is drivingly connected to at least one of the end walls slidably passing rod body and the housing interior fluid-tightly divided into two axially adjacent working chambers, of which at least one fluidbeaufschlagbar.

A known from DE-A-1426452 membrane drive of this type includes a housing which consists of two hood-shaped housing parts, which are attached to each other facing openings to each other. At their side walls framing the openings, the housing parts are fixed to one another by means of a bayonet connection device. The bayonet Binding device comprises a arranged on one housing part, radially projecting flange with circumferentially adjacent recesses and also arranged on the other housing part, acting as locking projections bent portions. In the mutually fixed state of the housing parts, the locking projections engage behind the existing between adjacent recesses of the flange edge portions of the flange, so that the housing parts are axially immovably fixed to each other. In the joining region of the two housing parts, an axially deformable membrane is arranged in the interior of the housing under seal, which divides two working chambers from each other. In accordance with a pressure difference prevailing between the two working chambers, a rod body which is coupled with the diaphragm in a movement-related manner is axially displaced.

Through the bayonet connection device, the two housing parts can be relatively quickly fixed in the context of a plug-and-turn movement together. However, resulting from the inter-engaged structures a highly rugged outer surface of the housing, which is very susceptible to contamination and difficult to clean. Not to be underestimated is also the risk of injury at the very exposed edges of the bayonet connection device.

A comparable problem is subject to in the

US 7,048,342 Bl described brake booster, the housing also consists of two interlocked housing parts. However, the joining process of the two housing parts is there a pure plug-in operation, because the locking is caused by bending of retaining tabs after the housing parts have been put together. The bayonet closure used according to DE 19642329 A1 for connecting fluid lines is also subject to a problem of contamination. A plug serving to receive a socket has a ring carried by two retaining clips, on which are formed two inwardly projecting hook-like locking projections, which are axially engaged behind by outwardly projecting locking projections of a plug-in socket. The locking projections of the sleeve come to lie in the region of two peripheral slots of the plug, which extend between the brackets and in which impurities can be deposited.

The invention has for its object to provide a diaphragm drive, which is easy to assemble in cleaning-friendly structure.

To achieve this object, it is provided in connection with the features mentioned that the locking projections of the bayonet connection device are concealed by the two housing parts from the outside from any angle invisible.

In this way, there is virtually a bayonet connection device arranged in the interior of the housing, the locking projections of which are shielded towards the outside and are not accessible from the outside of the housing. The housing can thus be quickly and easily assembled in the context of a plug-in rotation process, wherein in the assembled state, the occurrence of a rugged outer contour is avoided, which counteracts the deposition of impurities and favors effective cleaning. The membrane drive is therefore also ideally suited for use in a cleaning-intensive environment, for example for applications in the medical and pharmaceutical sector. Advantageous developments of the invention will become apparent from the dependent claims.

The attached to each other housing parts expediently with their two side walls under coaxial alignment axially into one another. The radially outer side wall has inwardly projecting outer locking projections, while the radially inner side wall has radially outwardly projecting inner locking projections. Outer and inner locking projections overlap in the radial direction, whereby they axially support each other axially with mutually axially facing locking flanks to ensure the cohesion of the housing parts.

The two side walls are expediently attached to one another in such a way that in the joining region there is a joint line lying on the outer surface of the housing and concentric with the longitudinal axis of the housing. In the region of this joint line, the two side walls are expediently abutting one another or are only minimally axially spaced from one another. Arranged on the two side walls and belonging to the bayonet connection device locking projections are located in the region of the outer surface of the housing opposite inside of the joint line and thus from the opposing sides of the joint line portions of the two side walls to the outside of the membrane drive, in all Directions covered. The joint line expediently concludes a joining plane radially on the outside, which is defined by two axially opposite and facing each other annular end faces of the two side walls. If these annular end surfaces abut each other or only minimally spaced from each other, can an optimal all-round shielding of the bayonet connection device can be ensured.

A preferred embodiment of the bayonet connection device provides that the outer locking projections ra ^¬ dial are arranged inside an annular support portion of a Sei ^¬ tenwand and the inner locking projections supporting other side wall has a flange-like and radially outwardly projecting annular cover portion axially protrudes in front of the end face of the support portion and this covers.

The inner locking projections are expediently radially on the outside on an annular support portion of the associated side wall, which projects coaxially into the annular support portion of the other side wall, wherein it is surmounted by the annular cover portion radially outward.

Conveniently, the mutually facing locking edges of all locking projections extend without inclination in a direction perpendicular to the longitudinal axis of the housing level, which can be described as a locking plane. In order to achieve an optimal axial preload between the two assembled housing parts, it is expedient if the membrane is clamped axially between the two side walls. Accordingly, the clamped section of the membrane is compressed axially during the production of the bayonet connection, so that it builds up a clamping force axially against each other in response to the locking projections.

However, at least some of the locking flanks can be readily provided with an axial slope, so that during manufacture of the bayonet connection during of the associated turning operation can build up axial biasing forces.

Conveniently, on the two side walls of the

Housing parts arranged stop means which limit the relative angle of rotation of the housing parts in the production of the bayonet connection. In this way, over-rotation is prevented and it is ensured that the cooperating components of the bayonet connection device automatically reach the correct relative position during assembly without costly control.

The stop means in particular comprise a arranged on the one side wall, aligned parallel to the longitudinal axis of the housing stop pin, which cooperates for the rotation angle limitation with a arranged on the other side wall and oriented in the circumferential direction of the longitudinal axis stop surface. The abutment surface may in particular be formed by an edge surface of a locking projection of the bayonet connection device.

The bayonet connection device are expediently associated with securing means which prevent unintentional turning back and accordingly unintentional release of the bayonet connection. These securing means are formed in particular in assembly with the stop means. Preferably, in this connection, the side wall, which is equipped with the stop face, has a locking recess in the area of the stop face into which the stop pin, which is furthermore anchored to the other side wall, can be inserted. The insertion movement can take place in particular in the context of a screwing operation when the stop pin is in threaded engagement with the side wall carrying it. Taking into account the design of the bayonet connection device according to the invention, the housing may in particular have a disk-like outer shape. It expediently has a center section contoured on the outside in the shape of a circular cylinder, in the region of which the outwardly concealed bayonet connection device is located, and to which an outer surface section, which tapers frustoconically on both sides, adjoins each other axially.

An expedient structure of the membrane drive provides that the two working chambers fluid-tight partitioning from each other membrane is clamped under axial bias of the side walls of the two assembled housing parts. The clamping results on the one hand an optimal sealing contact and on the other hand an effective support of the cohesion of the two housing parts.

In order to form the drive unit that is axially movable relative to the housing, the diaphragm is expediently screwed to the associated rod body. However, other types of connection are also possible.

Depending on the purpose and functionality of the membrane drive, the rod body can either enforce only one of the two end walls or it passes through the manner of a continuous rod simultaneously both end walls. In the latter case, it may be possible to selectively use either of the two on the opposite sides of the housing protruding end portions of the rod body for force picking.

If the rod body passes through both end walls, it is also possible to use the one end wall passing through the length section for the power tap and the longitudinal section passing through the other end wall for position detection and / or for position indication and / or position specification.

The membrane drive can be designed so that both of the membrane from each other sealed working chambers

fluid beaufschlagbar are. In this case, a control channel passing through the housing or the drive unit opens through each working chamber, through which a controlled fluid admission of the associated working chamber is possible. The diaphragm drive can thus be used in the manner of a double-acting linear drive.

There is also the possibility of arranging in one of the working chambers a membrane biasing the spring in a basic position return spring. This measure is recommended in particular when the working chamber receiving the return spring device is not used for fluid supply. In this way, a single-acting linear drive can be realized very easily.

In an advantageous construction, the return spring device consists of a relatively strong compression spring device. By applying the other working chamber, the restoring force can be overcome continuously, so that there is the possibility to use the diaphragm drive as a proportional drive, in which the realized stroke depends proportionally on the imposed fluidic pressure force. This mode of operation is additionally promoted by the membrane which can be moved without difficulty inside the housing.

The membrane drive can be used for a variety of drive tasks. In particular, it can be used wherever conventional short-stroke cylinders have been used to come. Above all, it is also suitable as a drive in the process industry and there in particular for the actuation of process valves of various kinds. It can be used for example for actuating a linear slide valve or as a drive for a pinch valve.

As drive medium for the delivery of the fluidic driving force in particular compressed air comes into question, although other compressed gases or hydraulic fluids are used as drive medium.

The membrane drive can be variably designed in one and the same size for different maximum strokes of the membrane or the drive unit containing the membrane. This is done in particular by providing one or more Hubbegrenzungselemente that are attachable in one or both working chambers on the end wall of the respective working chamber limiting end wall and act as a stop means for limiting the stroke. The maximum stroke of the drive unit is thus defined by the axial height of the installed Hubbegrenzungselementes. It is possible to install a plurality of stroke limiting elements axially staggered to vary the stroke. Alternatively, several Hubbegrenzungselemente can be provided with different heights, which are mounted alternatively in the respective working chamber. Such a structure of the membrane drive has the advantage that without changing the outer dimensions one and the same

Membrane drive can be used for different stroke ranges. Preferably, the at least one Hubbegrenzungselement is annular and arranged coaxially in a working chamber. For fixing to its place of use of the diaphragm actuator has advantageously on the outside of its housing via min ^¬ least one mounting interface. In this case, a central fastening interface in a central arrangement is preferably located on the outside of one of the two end-side end walls. This central mounting option makes it possible to align the diaphragm drive during its assembly over 360 ° in any angular orientation with respect to its longitudinal axis. Accordingly, required for the operation of the membrane drive fluid lines and possibly away leading electrical cables can be optimally positioned.

As a central mounting interface, in particular, a threaded hole is recommended in which a fastening screw can be screwed.

If the two housing parts, which is expediently the case in favor of a simple production and a low weight, consist of a plastic material, the attachment interface can also be formed on an insert made of metal, in particular in the

Injection molding of the associated housing part is embedded in the plastic material. In this way, despite a plastic housing, a high strength of the mounting interface can be ensured.

It is expedient to equip the membrane drive with position detection means for detecting at least one relative position of the diaphragm and the rod body comprising the drive unit relative to the housing. Depending on the configuration and arrangement, the position detection means may allow one or both stroke end positions of the drive unit and / or one or more intermediate positions to capture the drive unit. Also, a distance measurement to control the entire stroke range of the drive unit can be provided.

Sensors for position detection can be mounted, for example, on at least one of the two housing parts. It is thus possible to integrate sensors which occupy little space directly into at least one housing part.

For position measurement, the position detection means can have, for example, a position transmitter which responds to an actuating element, in particular a permanent magnet, moved along with the drive unit. Will the

Membrane drive used to operate a process valve, can be in this way very precisely monitor the current opening degree of the valve.

The membrane drive can also be equipped with an optical position detection without any problem. For this purpose, the rod body can have, for example, a bar code or line scale introduced, in particular, by laser processing, which can be scanned by an optical sensor arranged on the housing.

If an explosion-proof design of the membrane drive is desired, it is possible to resort to position-detecting means of non-electrical type instead of electrically operating position detection means. For example, magnetically actuable fluid switches can be used for position detection.

Further advantages and optional measures regarding the membrane drive are listed below. Since the housing of the membrane drive only consists of two hood-like housing parts, eliminating an additional cylinder tube and it results in a compact design with only a few components. The use of a diaphragm instead of a piston reduces the internal friction of the system and ensures an optimal response. In addition, no lubrication is required.

The membrane drive is expediently equipped with a cylindrical and preferably circular cylindrical rod body. Alternatively, however, a rod body with polygonal and in particular with a quadrangular cross-sectional contour is also suitable, since in this way it is particularly easy to realize an anti-twist device. A non-rotating, in particular as a square profiled rod body has the advantage that the membrane is not subjected to torsional stresses, which benefits their life expectancy.

The absence of screws for mutual fixing of the housing parts reduces the manufacturing costs. However, the fastening measures used for mutual fixation of the housing parts can nevertheless be configured without problems so that the housing parts are detachably joined together and can also be separated from each other for repair purposes at any time.

The drive unit can be equipped inside the housing with rubber-elastic buffer means, which ensure a muffled impact in the end positions. Suitable end position buffers can, in particular, protrude axially over the membrane on both sides, so that upon reaching a stroke end position, they end on an end wall opposite the drive unit can meet. The end position buffers are expediently designed as direct components of the membrane.

The housing parts fastened to one another according to the invention can consist of metal as well as of a polymer and in particular of a plastic material.

If a rod body passing through both end walls is used, at least the longitudinal section passing through an end wall can be used for limiting the stroke and / or for detecting the position of the drive unit. For example, an actuating element which cooperates with a fixed position sensor fixed to the housing and which is, for example, a magnetic element can be arranged on this longitudinal section of the rod body outside the housing. The actuating element may for example be carried by an adjusting nut, which is axially adjustably seated on an external thread of the longitudinal section of the rod body and which can be fixed by means of a lock nut. The position sensor is suitably attached directly or indirectly to the housing of the membrane drive.

At the projecting from the housing length of the rod body also an axially adjustable stop element in particular can be arranged, which can specify a certain axial position of the drive unit by cooperation with a arranged on the housing or formed directly from the housing counter-stop.

The rod body can be in one piece or also in several parts. It may, for example, have two rod body elements, which are attached to the membrane from opposite sides and which each have one of the abutments. form closure wall passing through lengths of the rod body.

For the membrane is recommended by a fiber assembly and / or by a tissue reinforced structure. The reinforcing means may in particular be arranged on one side outside or centrally in the interior of the membrane material. As a material for the membrane is recommended rubber or silicone or a thermoplastic polyurethane. In any case, it is advantageous if the membrane material is not only flexible, but also elastically deformable.

The membrane drive can additionally be equipped with light-emitting means that signal the achievement of at least one specific stroke position of the drive unit.

If the rod body is used for position detection of the drive unit, all common query options come into question. In addition to the optical scanning already mentioned, it goes without saying that magnetic scanning is also possible by, for example, embedding in the rod body a magnetic material which can be detected by a magnetic-field-sensitive position sensor or displacement transducer.

For the rod body is particularly recommended a structure made of aluminum or stainless steel. The two housing cover are advantageously made without cutting.

The membrane drive enables the realization of very fast movements of the drive unit. This can be used, for example, for punching, riveting, punching, stamping, embossing, ejecting or sorting. The moving mass is very low. Since at least that working chamber, which is not penetrated by a rod body, hermetically close execution bar, the membrane drive can be energetically operated with very high efficiency. Also on lubrication measures in relation to the membrane can be omitted.

The invention will be explained in more detail with reference to the accompanying drawing ^¬ tion. In this show: a perspective view of a preferred embodiment of the membrane drive according to the invention with a view of the side of Anschlußöff openings, a side view of the membrane drive as viewed along arrow II of Figure 1, wherein the viewing direction is oriented perpendicular to the longitudinal axis of the housing of the membrane drive, an isometric Exploded view of the

Membrane drive, a longitudinal section of the diaphragm drive according to

Sectional plane IV- IV of Figure 2, wherein this sectional plane coincides with the longitudinal axis of the housing together and has a relative to the longitudinal axis of the housing axial and radial extent, another longitudinal section of the diaphragm drive according to sectional plane VV of Figure 4, with respect to that of Figure 4 is based lying sectional plane is rotated by 90 ° about the longitudinal axis of the housing,

FIG. 6 shows a perspective individual view of one of the two housing parts, FIG. 7 shows a perspective individual view of the other of the two housing parts,

Figure 8 is an axially oriented interior view of the housing part shown in Figure 6, and

FIG. 9 shows an axially oriented interior view of the housing part shown in FIG.

The designated in its entirety by reference numeral 1 membrane drive is designed for fluid-controlled Actuate supply, the fluid force is gelie fert from a deliverable and dischargeable fluidic drive medium fert. This drive medium is in particular compressed air. The membrane drive can also be operated by means of other gaseous drive media and also by means of liquid drive media.

The diaphragm drive 1 has a housing 2 with a longitudinal axis 3. It also has a relative to the housing 2 in the axial direction of the longitudinal axis 3 linearly movable drive unit 4. The relative movement of the drive unit 4 with respect to the housing 2 by the controlled Fluidbe aufschlagung side caused the drive medium.

The housing 2 has two hood-shaped housing parts 5 6, which are referred to below for better distinction as ers TES and second housing part 5, 6. Each housing part 5, 6 has an in particular substantially disc-shaped end-side end wall 5a, 6a and an integrally coaxially adjoining annular side wall 5b, 6b. Each housing part 5, 6 frames with its annular side wall 5b, 6b arranged at an axial distance from the associated end stirnsei end wall 5a, 6a opening 7a, 7b. The two housing parts 5, 6 are attached coaxially to each other with mutually facing openings 7a, 7b, wherein they together define a housing interior 8. With the cooperation of the two annular side walls 5b, 6b, the housing parts 5, 6 are fastened to one another.

Each housing part 5, 6 has expediently an at least substantially round and in particular circular outer contour, the example of only one in the transition region between the end-side end wall 5a, 6a and the ringför shaped side wall 5b, 6b outside of each housing part 5, 6 integrally formed connection eye IIa, IIb is interrupted. The connection eyes IIa, IIb extend rib-like in radia ler direction into the region of the radially oriented outer contour of the associated side wall 5b, 6b, wherein they have at their radially outwardly facing end surfaces each have a connection opening 12a, 12b, the supply and discharge of Drive medium is suitable.

The drive unit 4 has a membrane 13 arranged in the interior of the housing and extending there transversely to the longitudinal axis 3. The membrane 13 is expediently preformed substantially in the manner of a pot. It has flexurally flexible properties and consists in particular of a rubber-elastic membrane body, which is combined with an integrated or externally attached fabric reinforcement.

According to the design of the annular side walls 5b, 6b, the membrane 13 has, by way of example, a circular outer contour. It has radially on the outside a continuous circumferential, in particular bead-shaped fastening. ing edge 14, with which it is clamped between the two annular side walls 5b, 6b under axial bias. With the cooperation of the membrane 13 is the

Housing interior 8 fluid-tight divided into two axially consecutive, hereinafter referred to as the first and second working chamber 15a, 15b working chambers. The first connection opening 12a arranged on the first housing part 5 communicates with the first working chamber 15a via a first control channel 16a passing through the wall of the first housing part 5, while the second connection opening 12b arranged on the second housing part 6 passes over one wall of the second

Housing part 6 passing through the second control channel 16b communicates with the second working chamber 15b. Thus, through the two control channels 16a, 16b through each working chamber 15a, 15b be acted upon with fluid pressure or pressure relieved.

The drive unit 4 contains as a further component in addition to the membrane 13 also called rod body 17 rod-shaped member which is fixed at one end in the central region of the membrane 13 and which extends from the diaphragm 13 in the axial direction of the longitudinal axis 3, wherein it slidably through a the end-side end wall 5a of the first housing part 5 passing through

Passage opening 18 passes outwardly. The rod body 17 has a arranged outside the housing 2 Abgriffsabschnitt 22 on which the executed by the drive unit 4 movement or force exerted actuation force can be tapped, for example, a valve body with a

Actuate diaphragm actuator 1 combined process valve.

In the passage opening 18 suitably designed annular guide means 23 and sealing means 24 are arranged, which surround the rod body 17 coaxial and which ensure that the rod body 17 on the one hand with respect to the Housing 2 is guided exactly linearly displaceable and that on the other hand, a fluid outlet from the housing interior 8 is excluded through the passage opening 18 therethrough.

Expediently, the membrane 13 is fixed to the rod body 17 by means of a screw connection device 25. To this end, an exemplary fastening screw 26 engages from the side of the second working chamber 15b through the membrane 13 and is screwed into the rod body 17 so that the membrane 13 is clamped between the rod body 17 on the one hand and a screw head 27 of the fastening screw 26 on the other hand. The clamping also results in a fluid-tight connection, which prevents fluid overflow between the two working chambers 15a, 15b.

It is understood that the membrane 13 may be fixed by other fastening measures on the rod body 17, for example by riveting.

The drive unit 4 expediently also contains two support plates 28, the outer diameter of which is smaller than the inner diameter of the housing interior 8 and which adjoin the axial axis of the coaxial arrangement on both axial sides of the diaphragm 13 at the same. The support plates 28 are incorporated into the screw connection means 25 and are located with axial bias of opposite axial sides of the membrane 13 at. At their radially outer edge region, the support plates 28 may be convexly rounded towards the membrane 13, so that a respective curved support surface 29 results, on which the membrane 13 can support and roll off, if it is used for the purpose of actuating the drive unit 4 is deflected axially by appropriate fluid loading. The support plate 28 may for example consist of a disc which may be bent axially on the outer edge to form the support surface 29.

In the exemplary embodiment, both working chambers 15a, 15b can be acted upon by a fluidic drive medium. Depending on the thus set pressure difference between the two working chambers 15a, 15b can be caused in this way an axial deflection of the radially within the clamped attachment edge 14 lying portion of the membrane 13, so that also the rod body 17 moves accordingly. In this way, a linear drive movement 34 of the drive unit 4 results in the axial direction of the longitudinal axis 3 relative to the housing 2.

If both working chambers 15a, 15b controlled by a fluid drive medium can be acted upon, there is a double-acting design of the diaphragm actuator 1, in which the drive unit 4 can be actuated in both axial directions by means of fluid force.

However, the membrane drive 1 can also be designed as a single-acting drive, wherein only one of the two working chambers 15a, 15b is formed fluidbeaufschlagbar or used for Fluidbeaufschlagung and wherein in one of the two working chambers 15a or 15b a return spring means 33 is arranged, on the one hand on the housing 2 and on the other hand supported on the drive unit 4 and by which the drive unit 4 is biased in a basic position. Such a return spring device 33 is indicated schematically in the drawing. It is designed in particular as a compression spring device and expediently designed as a coil spring device, wherein they are in the Housing interior 8 arranged longitudinal portion of the rod body 17 coaxially encloses.

An optional return spring device 33 can be supported by the drive unit 4, in particular on one of the abovementioned support plates 28.

In order to keep the drive unit 4 in the pressureless state in a stable basic position, the return spring means 33 may also be present when the diaphragm drive 1 is used as a double-acting drive.

The linear drive movement of the drive unit 4, which can be brought about by controlled fluid admission, is indicated in the drawing at 34 by a double arrow.

The drive unit 4 is expediently movable between two Hubendlagen. One of the stroke end positions is the basic position explained above. In each stroke end position, the drive unit 4 is supported on the inner surface of one of the two front end walls 5a, 6a.

The clamped fastening edge 14 of the membrane 13 expediently extends in a plane perpendicular to the longitudinal axis 3 mounting plane. This attachment plane is in particular a median plane for the possible axial deflection movement of the diaphragm 13. In one stroke end position, the diaphragm 13 is deformed starting from the fastening plane in the direction of the one end end wall 5a, in the other stroke end position it is in the direction of the other end end wall 6a deformed. In each stroke end position of the drive unit 4, the membrane 13 expediently a pot- or cup-like shape. On the outside of the housing 2 is expediently at least one attachment interface 35, via which the housing 2 of the membrane drive 1 can be attached to an external structure. By way of example, such a fastening interface 35 is arranged axially on the outside of the second housing part 6, which is not penetrated by the rod body 17, in particular at a central location, so that it is penetrated by the longitudinal axis 3.

The central fastening interface 35 is realized in particular in the form of a threaded hole coaxial with the longitudinal axis 3, by means of which the housing 2 can be externally fastened in the context of a screw connection.

An advantage of the central attachment interface 35 is that the housing 2 is relatively arbitrarily alignable relative to the longitudinal axis 3, before the final attachment takes place. In this way, the housing 2 can be variably oriented in terms of angle of rotation in accordance with the conditions prevailing at the place of use. In particular, the connection openings 12a, 12b can thereby be optimally oriented.

Notwithstanding the embodiment, the rod body 17 may also be formed so that it completely penetrates the housing interior 8 axially and also one on the second

Housing part 6 formed further passage axially traversed. Such a rod body 17 may be formed either in one piece or have a plurality of, in particular in the region of the membrane 13 interconnected rod elements.

In such a membrane drive 1, two tap sections 22, which are oriented axially opposite one another, can be arranged. drive unit 4 are provided for optional use.

If a rod body 17 completely axially passes through the housing 2, at least one of the two end sections arranged outside the housing 2 can be used for position detection and / or stroke adjustment of the drive unit 4.

As indicated schematically in the drawing, the membrane drive can have at least one stroke limiting element 36 arranged in the interior of at least one working chamber 15a, 15b which can be fixed or fixed to the axial inner surface of at least one end-side end wall 5a, 6a facing the membrane 13. With the aid of such a stroke-limiting element 36, the stroke end position of the drive unit 4, which is normally predetermined directly by an end-side end wall 5a, 6a, can be set differently. The inserted stroke limiting element 36 limits the axial stroke of the drive unit 4 and thereby makes it possible to make a variation of the stroke provided by the drive unit 4 without changing the basic structure of the membrane drive.

The Hubbegrenzungselement 36 may be fixed, for example by a screw or an adhesive connection on the associated housing part 5, 6. It is possible to install several Hubbegrenzungselemente 36 in cascaded form at the same time to define depending on the number of installed Hubbegrenzungselemente 36 different maximum strokes. It is also possible to provide a plurality of stroke limiting elements 36 of different lengths, which can alternatively be installed in the housing 2 depending on the desired maximum stroke. The Hubbegrenzungselement 36 is suitably annular and may preferably be installed with respect to the longitudinal axis 3 coaxial alignment. It is a separate with respect to the housing 2 component that is installed only with appropriate request.

Expediently, the membrane drive 1 is equipped with position detection means 37, which make it possible to detect at least one relative position of the drive unit 4 assumed with respect to the housing 2. The position detection means 37 can be designed to detect one or both stroke end positions of the drive unit 4 and / or to detect at least one intermediate position between the two stroke end positions and / or to continuously detect the entire stroke of the drive unit 4.

Particularly suitably designed position detecting means 37 comprise a on the outside of each housing part 5, 6 arranged and in particular in the immediate vicinity of a respective terminal eye IIa, IIb arranged mounting groove 38, in particular parallel to the longitudinal axis 3 with respect to the radially oriented longitudinal extent of the respective terminal eye IIa, IIb aligned is. Each mounting groove 38 is adapted to receive a position sensor 42, the contactless by a in the

Housing interior 8 arranged on the drive unit 4 and in particular designed as a permanent magnet actuating element 43 can be actuated. Each position sensor 42 responds, in particular, when the drive unit 4 has reached the assigned stroke end position.

The fastening groove 38 is formed in particular on a fastening rib 44 integrally formed on the adjacent connection eye IIa, IIb. By the fastening groove 38 due to the With respect to the longitudinal axis 3 radial longitudinal alignment of the mounting groove 38 opens out to the radially outer side of the housing 2, there, the required for the connection of the position sensors 42 electrical cables can be conveniently carried away.

The position detecting means 37 are indicated only schematically in the drawing.

One or both housing parts 5, 6 of the housing 2 expediently consist of a polymer material and in this case in particular of a plastic material. Here, the housing parts 5, 6 can be made very easily and inexpensively without cutting. In addition, the membrane drive 1 in this case has a low weight. It is understood, however, that a metal version is possible, wherein the housing parts 5, 6 are made in particular of aluminum or stainless steel. A realization of composite materials is possible.

The two housing parts 5, 6 are fastened to one another in an advantageous manner by means of a bayonet connection device 45. To produce the bayonet connection, the two housing parts 5, 6 with openings 7a, 7b facing one another can be axially assembled in advance in a first step and rotated relative to one another in a second step. The direction of the axial Zusammensteckens coincides with the axial direction of the longitudinal axis 3. The axis of rotation for the rotational movement is formed directly from the longitudinal axis 3.

The bayonet connection device 45 is expediently detachable. Thus, the two housing parts 5, 6 by a reverse movement - first Zurückdre- hen and then pulling apart - if necessary, be separated from each other again.

For the necessary axial bias between the two housing parts 5, 6 expediently ensures the between the two end-side end walls 5a, 6a clamped mounting edge 14 of the existing at least partially made of a material having elastomeric properties membrane 13th

The bayonet connection device 45 has arranged on the first housing part 5 first Verriegelungsvorsprün ge 46 a and arranged on the second housing part 6 second locking projections 46 b. When manufactured bayonet connection, the first and second locking Ver Verprünge 46 a, 46 b engage behind each other on axially facing sides. A special feature of the bayonet connection means 45 is that the locking projections 46a, 46b in the assembled state of the housing 2 by the two housing parts 5, 6 are concealed or covered in from the outside from the viewpoint invisible manner. In this way, an outer contour of the membrane drive, which has little tendency to contamination, which is very easy to clean and results in no risk of injury due to particularly exposed and possibly sharp-edged parts.

The two housing parts 5, 6 dive axially into one another in their joining area un coaxial alignment. By way of example, the end-side end wall 6a of the second housing part 6 is radially outwardly of the annular side wall 5b of the first part over at least part of its length

Enclosed part 5. It can therefore be said that the annular side wall 5b of the first housing part 5 lies outside in the joining region, while the annular side wall 6b of the second housing part 6 is radially inward. On the basis of this constellation is also the further description of the bayonet connection means 45. It is understood, however, that a reverse assignment of the housing parts 5, 6 is possible, so that the annular side wall 5b axially dips into the annular side wall 6b.

The side wall 5b of the first housing part 5 has an annular to the longitudinal axis 3, annular first support portion 47a. The first locking projections 46a, also referred to below as outer locking projections 46a, are arranged on the radially inner side of the first support section 47a. A plurality of first and outer locking projections 46a are distributed in the direction of the longitudinal axis 3 along the first support portion 47a at a mutual distance from each other. Accordingly, between each in the circumferential direction of the first support portion 47 a successive outer locking projections 46 a results in both an axially and radially inwardly open gap, which is hereinafter referred to as the outer gap 48 a. Thus, in the circumferential direction of the first support portion 47a, outer lock protrusions 46a and outer spaces 48a are sequentially arranged.

The annular side wall 6b of the second housing part 6 has an annular second support portion 47b, which is also arranged coaxially with the longitudinal axis 3. It protrudes axially toward the first housing part 5. The hereinafter also referred to as inner locking projections second locking projections 46b are disposed on the radially outer side of the annular second support portion 47b, wherein their number corresponds to that of the outer locking projections 46a. Between in the circumferential direction of the The support portion 47b, respectively adjacent to each other inner locking projections 46b is located axially to the first housing part 5 and at the same time radially outwardly open space, which is referred to below as the inner gap 48b. In this way, at the second supporting portion 47b, a plurality of inner locking projections 46b and inner spaces 48b distributed circumferentially are arranged alternately successively.

In the circumferential direction of a support section 47a, 47b, the extension around the longitudinal axis 3 of the housing 2 is meant.

The first support section 47a has an axial annular first end face 52a oriented toward the second housing part 6. The second support section 47b has at its end facing the first housing part 5 an axially oriented annular second end face 52b. The outer locking projections 46a expediently connect directly to the first end face 52a, while the inner locking projections 46b expediently directly adjoin the second end face 52b.

Between each locking projection 46a, b and an opposite portion of the associated housing part 5, 6 there is a groove-shaped gap 53a, 53b, which is open in the case of the first housing part 5 radially inward and in the case of the second housing part 6 radially outward. The groove-shaped intermediate spaces 53a, 53b merge in the circumferential direction of the support section 47a, 47b into a subsequent intermediate space 48a, 48b

When assembling the housing 2, first, the two housing parts 5, 6 are axially plugged together, so that the second Supporting portion 47b is inserted coaxially into the first support portion 47a, wherein at the same time the one at each

Housing part 5, 6 arranged locking projections 46 a, 46 b in each case one of the other housing part 6, 5 arranged intermediate spaces 48 b, 48 a dive. The housing parts 5, 6 are inserted axially into one another so far that the locking projections 46a, b of the respective housing part 5, 6 come to rest at the same axial height with the groove-shaped interspaces 53a, 53b of the respective other housing part 6, 5. Starting from this position are the two

Housing parts 5, 6 in the next step so far against each other until the arranged on the two support portions 47a, 47b outer and inner VerriegelungsvorSprünge 46a, 46b engage behind in pairs. The outer and inner locking projections 46a, b overlap each other in the radial direction with mutually axially facing locking flanks 54a, 54b and are supported against one another with these locking flanks 54a, 54b in the axial direction.

Between the abutting locking flanks 54a, 54b there is an axial prestress caused by the membrane 13 clamped between the two housing parts 5, 6.

By a special design of the two housing parts 5, 6 it is achieved that both the outer and the inner locking projections 46a, 46b are concealed towards the outside of the housing 2. It is even the case that the entire bayonet connection device 45 is hidden concealed by the two housing parts 5, 6 from outside the housing 2.

In order to achieve this, on the one hand, the first support section 47a carrying the outer locking projections 46a passes through. formed closed without a break, so that it completely covers the enclosed by him components of the bayonet connection device 45. These are, on the one hand, both the outer latching projections 46a disposed on themselves and the inner latching projections 46b engaging in the groove-shaped intermediate spaces 53a of the first housing part 5. The first support portion 47a thus forms a bayonet connecting device 45 radially outwardly shielding radial shielding wall. The same is preferably formed on its radial outer surface smooth surface and in particular circular cylindrical.

In the direction of the end-side end wall 5 a of the first housing part 5, the components of the bayonet connection device 45 are shielded directly from the wall of the first housing part 5.

Towards the end-side end wall 6a of the second housing part 6, the components of the bayonet connection device 45 are shielded by the wall of the second housing part 6. This is achieved in that the two housing parts 5, 6 connect to each other axially so that between them only one lying on the radial outer surface of the housing 2 and concentric with the longitudinal axis 3 hinge line 55 is visible. In the area of this joint line 55, the two housing parts 5, 6 are only minimally spaced from each other or are even directly to each other.

To achieve this design is on the second

Housing part 6 expediently formed to the second support portion 47b coaxial annular wall portion which is designated by its function as a cover portion 56 and the flange protrudes radially outward. The cover portion 56 is axially spaced from the second support section arranged on the internal locking projections 47b, 46b and defines with the inner Ver ^¬ Reset of projections 46b each having a groove-shaped interstices of the already mentioned 53b.

The annular cover section 56 has a radial extent such that it protrudes in front of the annular first end face 52a of the first support section 47a and expediently completely covers it. In this case, the cover section 56 lies opposite the first end face 52a formed on the first support section 47a with a further, axially oriented end face 57.

The abovementioned joint line 55 forms the end line of the outer surface 61 of the housing 2 of a joining plane formed between the two housing parts 5, 6, which is defined by the mutually facing annular end faces 52a, 57.

Conveniently, the annular cover section 56 terminates radially outwardly axially flush with the outer surface of the adjoining first support section 47a. In this way, the formation of an edge is avoided.

Thus assembled, the housing 2 has an outer circular cylindrical contoured central portion 62 which is defined by itself on the joint line 55 axially adjoining radial outer surface portions 63, 64 of the annular side wall 5b of the first housing part 5 and the cover portion 56 of the second housing part 6.

Particularly compact and easy to clean, the design of the housing 2 proves to be particularly useful when said central portion 62 axially on both sides each a frusto-conical contoured outer surface portion 65a, 65b of the housing 2 connects, extending in each of the other

Housing part 6, 5 pioneering direction tapers. In this way, the housing 2 may have a total disk-like shape.

If one wishes to rely on the mutual axial clamping of the two housing parts 5, 6 not only on the biased by the clamped membrane 13 bias, the locking edges 54a, 54b of the locking projections 46a, 46b at least partially relative to the peripheral wall of the associated support portion 47a, 47b with be provided a slope. The exemplary embodiment does not require such additional measures, in that here the locking flanks 54a, 54b of all the locking projections 46a, 46b extend without a slope in a plane perpendicular to the longitudinal axis 3 of the housing 2.

In order to ensure that the two housing parts 5, 6 are twisted into the correct relative rotary angle saw when the bayonet connection is made, suitable stop means 66 are expediently arranged on the two annular side walls 5b, 6b.

The stop means 66 comprise an exemplary arranged on the side wall 6b of the second housing part 6 stop pin 67 which is screwed into an axial threaded bore 68 of the cover 56. He stands in the axial direction over the end face 57 of the cover 56. It is expediently located in a region adjoining one of the inner locking projections 46b in the circumferential direction of the second support section 47b. It is located on the side wall 5b of the first housing part 5 stop surface 72. It is based on the longitudinal axis 3 as a center on the same circular line as the stop pin 67. It is conveniently immediately adjacent to one of the outer locking projections 46a.

When the two housing parts 5, 6 are put together, the stopper pin 67 dips into that outer gap 48 a, which is bounded on one side by the stop surface 72. The two housing parts 5, 6 can now be rotated so far against each other until the stop pin 67 runs onto the stop surface 72. Then the desired relative rotational position between the two housing parts 5, 6 is found, in which the bayonet connection device 45 is correctly effective.

The bayonet connection device 45 are expediently also associated with securing means 73, with which, after produced bayonet connection a reverse rotation between the two housing parts 5, 6 can be realized. It can be prevented in this way unintentional release of the bayonet connection.

By way of example, the securing means 73 are at least partially formed by the stop means 66. More precisely, the stopper pin 67 also acts as a locking pin 74 which is positively inserted into a locking surface 75 of the first housing part 5 adjacent to the stop surface 72 in the axial direction of the longitudinal axis 3, when the desired rotational angle position between the two housing parts 5, 6 is reached. The locking recess 75 adjoins the stop surface 72, in particular in the axial extension. The locking pin 74 is in particular a threaded pin, which is received screwed into the threaded bore 68. To lock and secure the relative rotational position between the two housing parts 5, 6, it can be screwed from the outside with a suitable screwing tool, so that it dips into the locking recess 75.

It is understood that the securing means 73 may also be formed independently of the stop means 66.

Claims

claims

1. fluid actuated diaphragm drive, with a longitudinal axis

(3) having housing (2) which has two in each case one of two in the axial direction of the longitudinal axis (3) at a distance opposite end-side end walls (5a, 6a) forming hood-shaped housing parts (5, 6), each one of an annular Side wall (5b, 6b) have framed opening (7a, 7b) and the common boundary of a housing interior (8) facing each other with openings (7a, 7b) coaxially to each other and in the region of the annular side walls (5b, 6b) by a yourself

behind the locking projections (46 a, 46 b) of the housing parts (5, 6) formed bayonet connection means (45) are fastened together, and with a drive unit

(4) comprising a membrane (13) which is fixed between the two housing parts (5, 6) and which is drivingly connected to a rod body (17) which slidably passes through at least one of the end walls (5a, 6a) and which surrounds the housing interior (8 ) in a fluid-tight manner into two axially adjacent working chambers (15a, 15b), of which at least one is fluidbeaufschlagbar, characterized in that the locking projections (46a, 46b) of the bayonet connection means (45) through the two

Housing parts (5, 6) are hidden from the outside invisible from any angle.

2. Membrane drive according to claim 1, characterized in that the two annular side walls (5b, 6b) dive axially into each other, wherein the radially outer side wall (5b) radially inwardly projecting outer locking projections (46a) and the radially inner side wall (6b ) radially outwardly projecting inner locking projections (46b), and wherein the outer and inner locking projections (46a, 46b) radially overlap with axially facing locking flanks (54a, 54b).

3. Membrane drive according to claim 2, characterized in that the two annular side walls (5b, 6b) to form a on the outer surface (61) of the housing (2) lying and to the longitudinal axis (3) concentric joint line (55) are attached to each other in that the locking projections (46a, 46b) of both side walls (5b, 6b) are located in the area of the inside of the joint line (55) opposite the outer surface (61) of the housing (2) and of the sections opposite to the joint line (55) the two side walls (5b, 6b) are covered to the outside.

4. Membrane drive according to claim 3, characterized in that the joint line (55) of two axially opposite and facing each other annular end faces (52 a, 57) of the two side walls (5 b, 6 b) is formed.

5. Membrane drive according to one of claims 2 to 4, characterized in that the outer locking projections (46 a) radially inwardly on an annular support portion (47 a) of the one side wall (5 b) are arranged and the inner locking projections (46 b) carrying the other side wall (46 6b) has a flange-shaped and radially outwardly projecting annular cover portion (56) which projects in front of the end face (52a) of the support portion (47a).

A diaphragm actuator according to claim 5, characterized in that the inner locking projections (46b) are disposed radially outwardly on an annular support portion (47b) of one side wall (6b) coaxial with the annular support portion (47a) of the other side wall (5b). protrudes, wherein it is dominated by the annular cover portion (56) radially outwardly concentric.

7. Membrane drive according to one of claims 2 to 6, characterized in that the locking flanks (54a, 54b) of all locking projections (46a, 46b) extend without a slope in a longitudinal axis (3) of the housing (2) perpendicular plane.

8. diaphragm drive according to one of claims 1 to 7, characterized in that on the two side walls (5b, 6b) the relative angle of rotation of the housing parts (5, 6) in the manufacture of the bayonet connection limiting stop means (66) are arranged, which expediently also effect a reverse lock with manufactured bayonet connection.

9. membrane drive according to claim 8, characterized in that the stop means (66) on one side wall (6b) arranged stop pin (67), which cooperates for the rotation angle limitation with a on the other side wall (5b) arranged abutment surface (72), wherein the stop pin (67) for absolute rotation of the bayonet joint interconnected housing parts (5, 6) in a locking recess (75) of the stop surface (72) having side wall (6b) is insertable.

10. Membrane drive according to one of claims 1 to 9, characterized in that the housing (2) has an outer circular cylindrical contoured central portion (62) to which axially on both sides in each case a frusto-conical contoured outer ^¬ surface portion (65 a, 65 b) connects.

11. embankment drive according to one of claims 1 to 9, characterized in that the membrane (13) between the two side walls (5 b, 6 b) is clamped under axial bias.

12. Membrane drive according to one of claims 1 to 11, characterized in that both by the membrane (13) from each other separate working chambers (15a, 15b) are fluidbeauf- beatable and / or that in one of the working chambers (15a) a membrane (13 ) is arranged in a basic position biasing return spring means (33).

13. Membrane drive according to one of claims 1 to 12, characterized in that it comprises at least one preferably annular Hubbegrenzungselement (36) which is fixable or fixed in at least one working chamber (15 a) on the inner surface of the associated end wall (5 a) and the limited maximum stroke of the membrane (13).

14. Membrane drive according to one of claims 1 to 13, characterized in that one of the housing parts (5, 6) outside centrally on a front end wall (6a) formed in particular by a longitudinal axis (3) of the housing (2) coaxial threaded hole central Attachment interface (35).

15. Membrane drive according to one of claims 1 to 14, characterized in that it with position detecting means (37) for detecting at least one with respect to the housing (2) assumed relative position of the membrane (13) and the rod body (17) comprehensive drive unit (4) is equipped ^¬ .