DE20118410U1 - Sealing device and fluid technology device equipped therewith - Google Patents

Description

G 19718 - 8 August 2001

FESTO AG & Co. 73734 Esslingen Sealing device and fluid power equipment equipped with it Furnishings

The invention relates to a sealing device for fluid-tightly connecting two fluid channels of two bodies attached to one another. The invention further relates to a fluid technology device with a fluid technology component which has a first body equipped with at least one first fluid channel, to which a second body equipped with at least one second fluid channel can be attached or is attached, and which contains a sealing device for fluid-tightly connecting the two fluid channels when the first and second bodies are attached to one another.

Measures of this kind are evident, for example, from EP 0688958 Bl. This describes a valve arrangement with a connecting part that has a plate-like first body that is equipped with a plurality of first fluid channels. The fluid channels open into individual mounting surfaces on the first body, to each of which a fluid technology component in the form of a valve can be attached. The valves have a second body, formed for example by the valve housing, with one or more second fluid channels that are aligned with the first fluid channels of the connecting plate when the valves are mounted.

In order to create a tight connection between the fluid channels that are assigned to each other, sealing devices are assigned to the channel pairs. These have the shape of hose connectors, each of which extends a little way into the fluid channels that are aligned with each other. Although the hose connectors can be grouped together in sealing plates, they are not particularly easy to install. In particular, it is difficult to attach a valve to the sealing devices that are already installed on the connection plate, since the hose connectors have to be threaded into the fluid channel openings of the valve.

As an alternative design, the applicant is also aware of sealing measures in which so-called round cord seals are placed in the peripheral area of the aligned channel openings between the two bodies attached to one another. However, such seals have the problem of only a small axial tolerance compensation, so that sealing problems can arise in particular when components are to be attached to one another that have a large number of fluid channel pairs arranged at a distance from one another and which are to be sealed. Such a problem arises, for example, when several valves are combined to form an assembly and this assembly is to be mounted as a unit on a connection plate.

It is the object of the present invention to provide a sealing device and a fluid power device equipped therewith, in which the sealing measures have a

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ensure good tolerance compensation and thus high sealing quality.

This object is achieved on the one hand by a sealing device for fluid-tight connection of two fluid channels of two bodies attached to one another, designed for insertion into the end section of the first fluid channel provided on the one, first body, with a sealing head which, when inserted into the end section, is movable in the longitudinal direction of the channel relative to the end section of the first fluid channel, which has front-side first sealing means for sealingly contacting the body surface of the second body enclosing the mouth of the other, second fluid channel and which has peripheral second sealing means for sealingly contacting the channel wall of the end section of the first fluid channel, and with spring means for resiliently supporting the movable sealing head with respect to the first body equipped with the sealing device, which can hold the sealing head in a basic position protruding further from the first fluid channel when the bodies are separated from one another, from which the sealing head can be moved by the second body to be attached against the spring force into a working position pushed further into the first fluid channel, wherein the second sealing means can slide along the channel wall of the first fluid channel.

Furthermore, the invention is achieved by a fluid power device, with a fluid power component, which has a first fluid channel equipped with at least one first fluid channel.

Body to which a second body of a further fluid technology component, equipped with at least one second fluid channel, can be attached or is attached, and with a sealing device for fluid-tightly connecting the two fluid channels when the first and second bodies are attached to one another, wherein the sealing device is inserted into the end section of the first fluid channel and contains a sealing head which is movable relative to this end section in the longitudinal direction of the channel, which has front-side first sealing means for sealingly contacting the body surface of the second body which encloses the mouth of the other, second fluid channel and which has circumferential second sealing means for sealingly contacting the channel wall of the end section of the first fluid channel, wherein the sealing device is further provided with spring means for resiliently supporting the movable sealing head with respect to the first body equipped with the sealing device, which can hold the sealing head in a basic position protruding further from the first fluid channel when the bodies are separated from one another, from which the sealing head can be pushed away from the second body against the spring force and while simultaneously sliding along the Channel wall of the first fluid channel can be moved into a working position further inserted into the first fluid channel.

The sealing device is designed in such a way that it only needs to be installed on one of the bodies to be joined together and the sealing contact with the other body is automatically achieved when it is joined. Threading into the fluid channel of the body to be joined is not necessary, as the

first sealing means can interact with the body surface of the second body that surrounds the second fluid channel. This makes it easy to compensate for tolerances in the radial direction. In addition, the spring means ensure axial tolerance compensation, since the working position of the sealing head is variable and can adapt to the position of the second body acting on it.

Advantageous further developments of the measures according to the invention emerge from the subclaims.

The spring means can be designed as a structural unit with the sealing head. This makes it possible to create a sealing device that is easy to handle and particularly easy to install.

The spring means can be independent components with respect to the sealing head. However, a one-piece construction is also possible.

The spring means are located in particular on the rear side of the sealing head opposite the first sealing means. They are preferably designed such that they can be supported with their end opposite the sealing head on a step in the interior of the first fluid channel.

It is not necessary that the sealing head is already loaded by the spring means in the basic position. For example, a design is possible in which the spring means in the basic position of the

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Sealing head are completely relaxed and are only compressed when the sealing head is axially displaced into the interior of the first fluid channel by the action of the second body. To fix the sealing device in the first fluid channel, a frictional contact between the sealing head and the channel wall can be provided. Stops for holding the sealing device in the first fluid channel can be expediently dispensed with.

It is advantageous if the sealing head has a support element, in particular made of rigid material, on which sealing material defining the first and second sealing means is provided. The sealing material can, for example, be molded onto the support element, whereby a design as an injection-molded part is recommended. The support element preferably stiffens the sealing head and prevents unfavorable deformations of the sealing material if the sealing head protrudes relatively far from the first fluid channel and large parts of its outer circumference are not supported by the channel wall.

The first sealing means are expediently formed by a ring-shaped, self-contained axial projection on the sealing head made of sealing material. In this way, a sealing edge with optimal sealing properties can be realized.

The second sealing means expediently contain a circumferential radial

projection, which can be designed as a sealing lip if required.

A further advantageous embodiment results from the fact that the outline of the second sealing means delimits a larger area than the outline of the first sealing means. The pressure prevailing in the fluid channels during operation can thus exert a compressive force on the sealing head in addition to the spring force and additionally preload it against the first body. It is then possible to reduce the spring force, which makes it easier to attach the second body, which has to push the sealing head back.

The invention is explained in more detail below with reference to the accompanying drawings, in which:

Fig. l a fluid power device in schematic representation in a side view,

Fig. 2 the arrangement from Fig. 1 in cross section according to section line II-II, whereby for the sake of simplicity only one sealing device is shown, which here assumes the working position, and

Fig. 3 shows the arrangement according to Fig. 1 and 2 with the bodies separated from each other, wherein the sealing device shown assumes its basic position.

The drawing shows a fluid power device designated in its entirety by reference number 1, which is used in the sector

fluid technology and particularly in the pneumatics sector.

The fluid power device 1 has a first fluid power component 2 and several second fluid power components 3 that are fixedly, preferably detachably, attached to the first fluid power component 2.

The first fluid power component 2 can be, for example, a connecting part, using which fluid lines 4 can be connected to the second fluid power components 3. Such a fluid line 4 is indicated by a dash-dotted line.

The second components 3 are preferably, at least in part, valves that can be used for fluid control, in particular electrically activated multi-way valves.

In the further description, reference is made to such a design, whereby the statements also refer to any other fluidic and mechanically connected fluidic components.

In the embodiment, the second fluid power components 3 are mounted in a row on a mounting surface 5 of the first fluid power component 2. In particular, it is provided that the fluid power components 2 are combined to form an assembly 6 that can be handled uniformly and that can be mounted as a unit on

the assembly area 5 is attached or removed from it * ··· ···* ··» ·« ··· ··

This assembly 6 can be designed in block form. Tie rods 10 can be provided for mechanically connecting the fluid power components 2 to one another. Screws 7 or other suitable fastening means can be used for detachably fastening the assembly 6 to the first fluid power component 2.

All second fluid power components 3 have a common fluidic connection to a feed line 8 and a discharge line 9 which can be used in particular as a vent line.

The second fluid technology components 3 each contain a second body 13, which is formed here by the valve housing. In the second body 13 there is at least one recess 11, in which normally at least one valve element not shown in detail in the drawing, for example a valve slide, is accommodated. The second bodies 13 of the individual second fluid technology components 3 are penetrated in the direction of the row by several connecting channels 14, which complement each other to form channels that run through the assembly 6 in the longitudinal direction and can be connected to the feed line 8 and the discharge line 9.

The valve members of the valves can be positioned in a manner known per se in order to output the working fluid, for example compressed air, fed in via the feed line 8 to connected consumers in a controlled manner and to discharge working fluid flowing back from the consumers via the discharge line 9. The

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Consumers are connected to the individual second fluid power components 3 via the first fluid power component 2. For this purpose, the first fluid power component 2 has one or more first fluid channels 15 for each associated second fluid power component 3, which pass through the main body of the first fluid power component 2, referred to below as the first body 12, in particular transversely to its longitudinal direction.

In the exemplary embodiment, two first fluid channels 15 are assigned to each second fluid technology component 3, although there may also be fewer or more such first fluid channels 15. The first fluid channels 15 open out with a connection end 17 to a connection surface 18 of the first body 12, where the already mentioned fluid lines 4 leading to the consumers can be connected.

On the opposite side, the first fluid channels 15 open out at the assembly surface 5, which is located in particular on the longitudinal side of the first body 12 opposite the connection surface 18 and which is divided into individual mounting surfaces, on each of which one of the second bodies 13 of the second fluid technology components 3 is mounted.

The second fluid technology components 3 are each equipped with one or more second fluid channels 16, the number of which corresponds in particular to that of the first fluid channels 15 opening out at the associated mounting surface. The second fluid channels 16 open out into the recess 11

and on the other hand on a body surface 21 of the second body 13 facing the assembly surface 5.

When the two first and second bodies 12, 13 of the fluid technology components 2, 3 are placed against one another, the first and second fluid channels 15, 16 are assigned in pairs. The first channel openings 22 of the first fluid channels 15 provided on the assembly surface 5 are each aligned opposite a second channel opening 23 of the second fluid channels 16 provided on the body surface 21. The end sections of the assigned first and second fluid channels 15, 16 which adjoin the first and second channel openings 22, 23 are in particular aligned coaxially with one another.

By appropriate actuation of the second fluid technology components 3, which are valve-like in the embodiment, a connection between the first fluid channels 15 and the feed line 8 or the discharge line 9 can be selectively established or interrupted.

For fluid-tight connection of the respective corresponding first and second fluid channels 15, 16, each of these fluid channel pairs is assigned a special sealing device 24. For reasons of clarity, the sealing device 24 in Fig. 2 and 3 is only shown in connection with such a fluid channel pair.

The sealing device 24 is installed on one of the two bodies 12, 13. In the embodiment, it is located

on the first body 12, wherein all first fluid channels 15 are provided with such a sealing device 24. The further description is based on such an embodiment, although it would be possible to place individual or all sealing devices 24 on the second bodies 13.

The sealing device 24 is designed such that it can be inserted into the end section 25 of the first fluid channel 15 ending with the first channel opening 22. The insertion assembly takes place through the first channel opening 22. Figures 1 and 3 show the sealing device 24 in the already inserted state of use.

The sealing device 24 can be conveniently inserted by simply inserting it axially into the first fluid channel 15. This can be done manually; special assembly tools are not required.

The following statements refer to the state of use of the sealing device 24, unless otherwise stated.

The sealing device 24 has a sealing head 26 which is guided in the end section 25 of the first fluid channel 15 in the channel longitudinal direction 27, which is indicated by a dot-dash line. The sealing head 26 can assume different positions in which it protrudes more or less far through the first channel opening 22 over the assembly surface 5.

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The sealing head 26 has an axial through-opening 28 and can, for example, have a sleeve-like or hollow cylinder-like shape.

On the front side, on the outer front side facing the second body 13, the sealing head 26 is equipped with first sealing means 32. These expediently have the shape of a ring-shaped, self-contained radial projection that borders the through-opening 28. This can taper towards the free end, seen in cross section, so that a type of sealing edge is created.

The first sealing means 32 are designed in their shape and in the cross-section delimited by them such that, when the second body 13 is attached to the first body 12, they are in sealing contact with the body surface 21 of the first body 12 around the associated second channel opening 23.

The contact pressure is at least partially provided by spring means 34, by means of which the sealing head 26 is resiliently supported with respect to the first body 12.

In the dismantled state of the second body 13 (see Fig. 3), the spring means 34 are relaxed. They represent a kind of movement stop for the sealing head 26, which they hold in a basic position protruding further from the first fluid channel 15. When the second body 13 is attached, the sealing head 26 is pushed in the area of the first sealing means 32 by the facing body surface 21 of the second

Body 13 is acted upon and pushed axially further into the interior of the first fluid channel 15 against the restoring force of the spring means 34. The maximum pushed-in state is reached when the two bodies 12, 13 are in contact with one another or, due to other circumstances, are already fixed in a certain relative position beforehand. The position then assumed by the sealing head 26 is referred to as the working position and is shown by way of example in Fig. 2.

In this working position, the sealing head 26 with its first sealing means 32 is prestressed in the peripheral region of the associated second channel opening 23 against the body surface 21 of the second body 13. This results in a fluid-tight contact.

In the working position, the sealing head 26 can certainly continue to protrude a little from the associated first fluid channel 15, but it can also be completely sunk into the first fluid channel 15. The position depends, among other things, on the design of the cooperating body surface 21 and, for example, on whether it is raised or flat. Furthermore, the position also depends in particular on the distance between the assembly surface 5 and the body surface 21.

An advantage of the sealing device 24 is that the desired sealing contact is ensured regardless of how close the two bodies 12, 13 have come to each other in the joining area when assembled together. This is advantageous, for example, when several second

Bodies 13 are combined in an assembly 6, in which a mutual offset of the body surfaces 21 of the firmly connected second bodies 13 can occur. This provides automatic axial tolerance compensation.

While the first sealing means 32 serve to seal between the sealing head 26 and the second body 13, the sealing head 26 is also equipped on the circumference with second sealing means 33, which establish a sealing contact between the sealing head 26 and the channel wall 35 of the end section 25 of the first fluid channel 15 receiving the sealing head 26.

The second sealing means 33 extend in the region of the radially outwardly oriented outer circumference of the sealing head 26 completely around the latter, so that an annular sealing contact is established between the sealing head 26 and the channel wall 35.

The second sealing means 33 expediently consist of at least one circumferential radial projection made of sealing material, which is expediently designed as a sealing lip.

If the sealing head 26 is axially displaced in the longitudinal direction of the channel according to the double arrow 36, the second sealing means 33 can slide along the channel wall 35 of the first fluid channel 15, whereby the sealing contact is constantly maintained. Thus, in every axial position of the sealing

sealing head 26, a sealing contact between the sealing head 26 and the channel wall 35 is provided.

This also has the advantage that material deformations occurring during operation of the fluid power device 1, such as thermal expansion, are automatically compensated.

In the exemplary embodiment, the first and second sealing means 32, 33 are formed from sealing material which is integrally formed on a support element 37 of the sealing head 26, which support element is made of rigid material. The support element 37 is a hollow body which is made of metal or a hard plastic, for example, and which is responsible for the strength of the sealing head 26. The support element 37 is preferably a polymer part. The sealing material 38 is preferably an elastomer material.

The support element 37 of the embodiment has a cross-section that is stepped several times in the axial direction, so that an inner end section 42 of smaller diameter pointing axially into the interior of the first fluid channel 15 and an oppositely oriented outer end section 43 of larger diameter are obtained. The sealing material 38 defining the first sealing means 32 is expediently located predominantly on the inner circumference of the outer end section 43. The sealing material 38 for the second sealing means 33 is expediently located on the outer circumference of the support element 37 and preferably on the outer circumference of the inner end section 43.

section 42 or in the transition area between the two end sections 42, 43.

The sealing material 38 could also be attached to the support element 37 in a manner other than by direct molding, for example by a press fit connection.

The support element 37 represents a reinforcement or reinforcement for the sealing material 38. It prevents the sealing material 38 from swelling when the sealing head 26 protrudes relatively far from the first fluid channel 15 in the working position and a relatively large gap between the two bodies 12, 13 has to be bridged.

The spring means 34 are expediently located on the rear side of the sealing head 26 opposite the first sealing means 32. They are supported at one end on a surface of the sealing head 26 oriented axially into the interior of the first fluid channel 15 and at the other end on a step 44 of the first fluid channel 15. In the exemplary embodiment, the step 44 is realized by successive channel sections of different diameters.

The spring means 34 can consist of a helical compression spring 45, comparable to the embodiment. Since the sealing head 26 engages with the inner end section 42 of the support element 37 in the helical compression spring 45, secure centering is achieved.

The spring means 34 can be firmly connected to the sealing head 26. However, it is also possible to design the sealing head 26 and spring means 34 as components of the sealing device 24 that are loose with respect to one another. With a firm connection, the advantage is a structural unit that can be handled like a single component.

The spring means 34 can also be connected in one piece to the sealing head 26. For example, it would be possible to extend the support element 37 into the interior of the first fluid channel and to design the extended section in such a way that spring properties are provided.

In the embodiment in the basic position shown in Fig. 3, the sealing head 26 is secured against loss by frictional engagement with the channel wall 35 of the first fluid channel 15. Thus, the sealing head 26 can be fixed to the second body 13 even without additional stop means.

The frictional connection can be implemented very easily by designing an elastically deformable area of the sealing head 26 with an oversize in relation to the cross section of the end section 25. It is possible that the sealing contact between the second sealing means 33 and the channel wall 35 already ensures the desired frictional fixation.

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The region of the second body 13 surrounding the first channel openings 22 is expediently provided with a chamfer 46 which facilitates the insertion of the sealing head 26 during installation in the first fluid channel 15.

The sealing means 32, 33 are expediently designed such that the area A ₁ delimited by the outline of the radially sealing second sealing means 33 is larger than the area A ₂ delimited by the axially sealing first sealing means 32. The area difference is an annular area which is oriented axially into the interior of the first fluid channel 15 and, in conjunction with the pressure prevailing in the first fluid channel 15 during operation, generates a pressure force F _D which is added to the spring force F _F. In this way, the axial seal experiences pressure support which depends on the level of the internal pressure prevailing in the fluid channels.

Taking into account the effective pressure force F _D, the spring force F _F can be designed to be relatively low if operation with excess pressure is intended. The spring means 34 are more important with regard to the sealing force to be applied if there is negative pressure in the fluid channels, as is the case in vacuum applications.

Claims (18)

1. Sealing device for fluid-tight connection of two fluid channels (15, 16) of two bodies (12, 13) attached to one another, designed for insertion into the end section (25) of the first fluid channel (15) provided on the one, first body (12), with a sealing head (26) which, when inserted into the end section (25), is movable in the channel longitudinal direction (27) relative to the end section (25) of the first fluid channel (15), which has front-side first sealing means (32) for sealingly contacting the body surface (21) of the second body (13) enclosing the mouth (23) of the other, second fluid channel (16) and which has peripheral second sealing means (33) for sealingly contacting the channel wall (35) of the end section (25) of the first fluid channel (15), and with spring means (34) for resiliently supporting the movable Sealing head (26) with respect to the first body (12) equipped with the sealing device (24), which can hold the sealing head (26) in a basic position protruding further from the first fluid channel (15) when the bodies (12, 13) are separated from one another, from which the sealing head (26) can be moved by the second body (13) to be attached against the spring force into a working position pushed further into the first fluid channel (15), wherein the second sealing means (33) can slide along the channel wall (35) of the first fluid channel (15). 2. Sealing device according to claim 1, characterized in that the spring means (34) are formed as a structural unit with the sealing head (26). 3. Sealing device according to claim 1 or 2, characterized in that the sealing head (26) and the spring means (34) are integrally connected to one another. 4. Sealing device according to one of claims 1 to 3, characterized in that the spring means (34) contain at least one helical compression spring (45). 5. Sealing device according to one of claims 1 to 4, characterized in that the spring means (34) are provided on the rear side of the sealing head (26) opposite the first sealing means (32). 6. Sealing device according to one of claims 1 to 5, characterized in that the spring means (34) are designed such that they can be supported with their end opposite the sealing head (26) on a step (44) in the first fluid channel (15). 7. Sealing device according to one of claims 1 to 6, characterized in that the sealing head (26) is fixed to the first body (12) in a frictionally locking manner in the basic position, in particular by the sealing contact between the second sealing means (33) and the channel wall (35). 8. Sealing device according to one of claims 1 to 7, characterized in that the sealing head (26) has a support element (37) consisting in particular of rigid material, on which sealing material (38) defining the first and second sealing means (32, 33), in particular in the form of elastomer material, is provided. 9. Sealing device according to claim 8, characterized in that the support element (37) consists of metal or hard plastic. 10. Sealing device according to claim 8 or 9, characterized in that the sealing material (38) is molded onto the support element (37), in particular by injection molding. 11. Sealing device according to one of claims 1 to 10, characterized in that the first sealing means (32) are formed by an axial projection on the sealing head (26) which is annularly closed and consists of sealing material. 12. Sealing device according to one of claims 1 to 11, characterized in that the second sealing means (33) are formed by a circumferential radial projection made of sealing material on the sealing head (26), in particular designed as a sealing lip. 13. Sealing device according to one of claims 1 to 12, characterized in that the outline of the second sealing means (33) delimits a larger area than the outline of the first sealing means (32). 14. Sealing device according to one of claims 1 to 13, characterized in that one body (13) belongs to a valve and the other body (12) belongs to a connection part equipped or to be equipped with the valve. 15. Fluid power device, with a fluid power component (2) which has a first body (12) equipped with at least one first fluid channel (15), to which a second body (13) of a further fluid power component (3) equipped with at least one second fluid channel (16) can be attached or is attached, and with a sealing device (24) for fluid-tightly connecting the two fluid channels (15, 16) when the first and second bodies (12, 13) are attached to one another, wherein the sealing device (24) is inserted into the end section (25) of the first fluid channel (15) and contains a sealing head (26) which is movable relative to this end section (25) in the channel longitudinal direction (27), which has front-side first sealing means (32) for sealingly contacting the body surface (21) of the second body (13) which encloses the mouth (23) of the other, second fluid channel (16), and which has circumferential second Sealing means (33) for sealingly contacting the channel wall (35) of the end section (25) of the first fluid channel (15), wherein the sealing device (24) is further provided with spring means (34) for resiliently supporting the movable sealing head (26) with respect to the first body (12) equipped with the sealing device (24), which can hold the sealing head (26) in a basic position protruding further from the first fluid channel (35) when the bodies (12, 13) are separated from one another, from which the sealing head (26) can be moved by the second body (13) against the spring force and while simultaneously sliding along the channel wall (35) of the first fluid channel (15) into a working position pushed further into the first fluid channel (15). 16. Device according to claim 15, characterized in that the sealing device (24) is designed according to one or more of the features of claims 1 to 14. 17. Device according to claim 15 or 16, characterized by a design of the one fluid power component (2) as a connection part equipped with a plurality of first fluid channels (15), which is equipped or can be equipped with a plurality of fluid power components (3), each having at least one second fluid channel (16) and designed as valves. 18. Device according to claim 17, characterized in that the fluid power components (3) designed as valves are combined to form an assembly (6).