WO2000046528A1

WO2000046528A1 - Sealing device

Info

Publication number: WO2000046528A1
Application number: PCT/IB2000/000119
Authority: WO
Inventors: Wilfried Starke
Original assignee: Technip Germany Gmbh
Priority date: 1999-02-05
Filing date: 2000-02-04
Publication date: 2000-08-10
Also published as: DE19906174C1

Abstract

The invention relates to a device for sealing the contact area between two contacting parts that can be displaced in relation to one another. One of said parts represents a blocking element (1) and the other one a sealing seat. Said sealing seat contains at least one sealing element that is formed by a strip of a spring steel sheet metal (2) that is bent in the shape of a hollow profile. Said hollow profile steel strip (2) is composed of sections (17, 18, 19, 20) that give a closed polygonal contour. The corners of said polygonal contour are filled with hollow profile corner elements (16) that have a practically rigid outer form vis-à-vis the effect of the sealing force. The corner elements are also supported by a resilient support in the direction of the sealing force. The front faces of said corner elements are provided with respective level sheet metal end sections. Said end sections are arranged in parallel to the direction of the sealing force and are positioned perpendicularly to the longitudinal axis of the adjacent sections (17, 18, 19, 20) of the hollow profile steel strip (2). The sections (17, 18, 19, 20) of the steel strip (2) that are adjacent to a respective corner piece (16) and that are cut perpendicularly to their longitudinal axis closely contact, especially slidingly contact, the respective sheet metal end sections (24) with their respective front faces.

Description

Sealing device

description

The invention relates to a device for sealing the contact zone between two relatively movable system parts, one of which forms a shut-off element and the other a sealing seat, according to the generic term of

Claim 1.

From the generic DE 195 21 916.3 A1 is known for sealing between two flap wings or a flap wing and a stop of a flue gas fitting, which is an elastic formed by a spring steel sheet strip

Contains sealing element. This sealing element contains two flat clamping edges arranged next to each other in parallel and pointing to the same side as well as an arcuate sealing zone between the clamping edges. The spring steel sheet strip can be fastened by means of a clamping device over the clamping edges to the desired part of the flue gas fitting.

The other part of the system, on which the counter surface of the sealing seat is arranged, comes into contact with the sealing element in the case of a seal in the apex region of the curved sealing zone with the exertion of a sealing force.

In the generic but not prepublished patent application DE 198 28 896 A1 of the applicant, a device is described which is intended in particular for use in flue gas fittings which are subject to strong thermal expansions. Thanks to its special design, it enables spring travel of up to 30 mm, for example. This device contains at least one Sealing element, which is formed by a spring steel sheet strip extending along the contact zone, which is bent in the shape of a hollow profile and the two longitudinal edges of which form tensioning edges, which on one of the two system parts between which the sealing is to take place, with a distance from one another that is at least 10% of the width of the sealing element is clamped. That’s it

Sealing element in the closed position of the shut-off element with a sealing zone which is convexly curved relative to the sealing seat by spring action with a sealing force on the sealing seat. This device is further characterized in that the sealing zone of the spring steel sheet strip is bent by plastic deformation in the form of a roof ridge with roof surfaces adjoining on both sides.

The two roof areas are aligned at an angle of 60 ° to 160 ° to each other. In addition, on the longitudinal edge of the two roof surfaces facing away from the ridge there is in each case a further, externally convex bend produced by plastic deformation, to which an at least in a first section flat side surface adjoins the free longitudinal edges of the clamping edge.

The spring steel sheet strip used in such sealing devices, on which the actual sealing zone is arranged, usually has a thickness which is on the order of about 0.5 mm. As a rule, these are

Seals around circumferential, ie self-contained seals, which are attached, for example, to the edge of a slide plate and are therefore laid in the shape of a polygon. The circumferential length of such a polyline is usually several meters and is composed of several partial lengths. In the area of the linearly loosely joined partial lengths, the joints are practically no problem with regard to their tightness, since the deformation of the spring steel sheet strips takes place there completely evenly. In the area of the corners of the polyline, however, there are opposing deformations on the abutting partial lengths, so that gaps are formed which lead to impermissibly strong leaks. A material connection e.g. by welding or

Gluing, which could possibly help, is not an option in the area of the joint due to the thin wall thickness of the spring steel sheet strip.

The object of the present invention is therefore to improve a sealing device of the generic type in such a way that the the hollow profile formed by the spring steel sheet strip is as tight as possible to the outside without stiffening of the sealing profile occurring in an unacceptable manner affecting the spring force of the spring steel sheet strip in the corner regions.

This object is achieved according to the invention by a sealing device with the

Claim 1 specified features. Due to the characterizing features of subclaims 2 to 10, this device can be further developed in an advantageous manner.

The invention provides for a generic sealing device that the corners of the polygon are filled with preferably hollow profile-shaped corner pieces, which in principle have a rigid outer shape, i.e. practically do not deform under the influence of the sealing force. However, these corner pieces can dodge in the direction of the sealing force, since they are mounted on a resilient support according to the invention. Furthermore, it is provided that the corner pieces are provided on the front side, that is to say on the sides facing the partial lengths of the spring steel sheet strip, with a flat end sheet which is arranged parallel to the direction of the sealing force and perpendicular to the longitudinal axis of the respectively subsequent partial length of the hollow profile-shaped spring steel sheet strip. These end plates each form a contact surface for the subsequent partial lengths of the spring steel strip. The

Part lengths are cut perpendicular to their longitudinal axis and lie with their front side close to the respective end plate. In principle, it would be possible to connect the spring steel sheet strips to the associated end sheet. However, it is much simpler and, with regard to the sealing effect, completely sufficient to slide the individual partial lengths close to the corresponding end plate. These measures ensure that the corner piece in the apex area of the angle of the respective corner offers a completely closed continuous sealing zone and despite the rigid design of the shape of the corner piece because of the resilient storage, evasion against the sealing force is possible in the same way as this also applies to the individual partial lengths of the

Spring steel sheet strip is the case.

The resilient support of the corner piece is expediently formed by a spring element, which can also be divided into several sub-elements, which is arranged within the hollow profile-shaped corner piece and at least It must of course be ensured that the deflection of this spring element is not hindered by the walls of the hollow profile-shaped corner piece. Spring elements are used with particular advantage as an open hollow profile with an essentially diamond-shaped head part in cross-section and a connected to it Base part are formed, which is formed by the side surfaces of the hollow profile running parallel at a distance from each other. The side surfaces at their lower ends should form tensioning edges for particularly simple fastening of the spring element. It is particularly advantageous if the side surfaces also have sliding surfaces for the parallel Form mutually tapering edges of the hollow-profile-shaped corner piece. The spring element preferably has a shape which essentially corresponds to the shape of the spring steel sheet strip used for the actual sealing f and also consists of spring steel. In a particularly preferred embodiment, the device according to the invention for sealing has a hollow profile-shaped element used as a sealing element

Spring steel sheet strips, as described in DE 198 28 896 A1, the spring elements within the corner pieces each having spring elements which are shaped in a manner similar to this spring steel sheet strips, although the side faces of the foot part are extended to form sliding faces

A particularly favorable operating behavior arises if the resilient support for the corner pieces each has a spring characteristic which at least approximately corresponds to the spring characteristic of the spring steel sheet strip of the actual seal.This requirement is not technically mandatory, but has the advantage that, for example, a flue gas flap is located on the circumference can form approximately equal sealing forces based on the unit length

The corner piece preferably has a significantly greater wall thickness than the spring steel sheet strip, in particular a wall thickness which is twice to five times greater

For example, the wall thickness can be 2 mm. This is sufficient in any case to form a corner piece as a welded construction from two hollow profile pieces which are mitered and assembled according to the corner shape. As a result of the considerably larger wall thickness of the corner piece compared to the wall thickness of the spring steel sheet strip, which for example is only 0. 5 mm, has one such corner piece has a significantly higher rigidity. If the corner piece were rigidly fixed, this would lead to an impermissible "hardening" of the sealing zone of the spring steel sheet strip. However, this is avoided by the resilient mounting of the corner piece.

Appropriately, a corner piece used according to the invention has an essentially box-shaped basic shape in cross section, with the surface side on which the counter surface of the sealing seat comes into contact with the outside when the sealing device is unloaded. In this way, a similarly linear sealing zone is formed on the outer surface of the corner piece, as is the case itself due to the ridge of the spring steel sheet strip described in DE 198 28 896 A1.

The invention is explained in more detail below on the basis of the exemplary embodiment illustrated in the figures.

Show it:

1 is a generic sealing device in the assembled state,

Fig. 2 is a partial plan view of the corner area of a

Flap wing with double seal according to the invention for a flue gas valve and

3 shows a section along line A-A in FIG. 2nd

1 shows in cross section a sealing device according to DE 198 28 896 A1 in assembled form. The unloaded state of the sealing element is shown with solid lines, while the deformation that has occurred is indicated by dashed lines in the temperature-loaded state. Essential element of

The device for sealing is the spring steel sheet strip 2 shown as a thick line. This has in its upper part a sealing zone 4 which is designed in the manner of a roof ridge with two flat roof surfaces 5. The bend in the sealing zone 4 has been produced by plastic deformation of the spring steel sheet strip 2. At the longitudinal edges facing away from the sealing zone 4 Roof surfaces 5 each have a further outwardly convex bend 6.These are joined by side surfaces 7, which are flat in a first part.The two rims of the spring steel sheet strip 2 are designated by the reference number 3 and are aligned plane-parallel to one another Side faces 7 each attached a further bend 8, which was also generated by plastic deformation, but is not convex, but is concave to the outside In order to bring the clamping edges 3 to the desired distance from each other, a rectangular hollow profile 9 has been inserted between them the outer sides of the two clamping edges 3 each have a terminal strip 10 or 11

The clamping edges 3 of the spring steel sheet strip 2 are clamped by means of a screw 12 between the two terminal strips 10, 1 1 and the hollow profile 9 arranged between them. While in the terminal strip 10 and in the hollow profile 9 only simple through holes are provided for the screw 12, the terminal strip 1 1 a suitable threaded hole for the thread of the screw 12. This allows the sealing device to be provided in a preassembled form without the use of a separate nut Flue gas valve assembled The part of the system to which the sealing device is to be attached (e.g. sealing seat on

Housing of a gas switch) is provided with the reference number 13. Like the hollow profile 9 and the terminal strip 10, it has a through hole suitable for the screw 12. The screw 12 is made much longer than it is per se for screwing with the threaded hole in the terminal block 1 1 would be necessary. Therefore, the free ends of the screw 12 can be inserted into these through bores on the system part 12 and can be firmly clamped to the latter by means of nuts 14

The spring steel sheet strip 2 forms a hollow profile, the cross section of which is essentially diamond-shaped, and the clamping edge 3, as it were, a foot on one

Form the corner of the rhombus of the cross section, so that a simple pre-assembly of the sealing device is possible In the exemplary embodiment shown, the two clamping strips 10, 11 each have a rounded longitudinal edge, the radius of curvature of which is adapted to the radius of curvature of the concave bend 8. The two clamping strips 10, 11 extend with their rounded long edge to the area of the bend 8 Mit The reference number 1 has been used to denote a piece of a shut-off element which bears against the curved sealing zone 4 while exerting a sealing force. The situation of the deformation of the spring steel sheet strip 2 by a strong thermal expansion has been shown in broken lines. Under the pressure of the shut-off element 1, the sealing zone 4 is shifted downward, so that on the one hand there is an increase in the angle in the area of the roof ridge and on the other hand there is a decrease in the angle in the area of the two bends 6, which also deviate somewhat to the outside. It can be clearly seen that the sealing device allows a very large spring travel despite its compact design. The spring stiffness is so great that, despite high flue gas speeds, no inadmissible vibrations of the spring steel sheet strip 2 occur, which could lead to its premature destruction.

In Figures 2 and 3 is an embodiment of an inventive

Device for sealing shown in sections as a top view or as a sectional view. It is a valve disc for a gas switch. This flap disc, which is designated by the reference symbol 15, is provided on its edge on each side surface with a circumferential double seal which is designed in the manner according to the invention. One can see in Fig. 2 the parallel and in

Spacing from each other hollow-profile-shaped spring steel sheet strips 2, which are joined in pairs in the corner area shown in the form of the partial lengths 17 and 18 or 19 and 20 via corner pieces 16. Since it is a right-angled corner region, the corner pieces 16 are each L-shaped in plan view. The corner pieces are composed of two miter cut sections of a hollow section made of sheet steel from e.g. 2 mm thick. In the joint area, the two legs of the corner pieces 16 are each tightly connected to one another by a weld seam. The joints between the coaxial parts of the spring steel sheet strip 2 (not shown) and between the partial lengths 17, 18, 19, 20 of the

Spring steel sheet strip 2 and the legs of the corner pieces 16 are each perpendicular to the longitudinal axis of the spring steel sheet strip 2 and the legs of the corner pieces 16. 3 shows the structure of the corner pieces 16 in detail. The corner pieces 16 have a head part with a box-shaped basic shape in cross-section, the outer side surface of which is curved outwards in a roof-like manner (curvature 25) Similar line-shaped contact zone running in the axial direction of the legs for the clean contact of the counter surface of the sealing seat, as is also the case with the spring steel sheet strip 2. On the inward broad side of the corner piece 16 is its otherwise closed hollow profile with parallel and spaced-apart edge surfaces 21 provided inside the hollow profile of the corner piece 16, a spring element 23 is arranged, which consists of two identical sub-elements, one of which is inserted into each of the two legs, while the partial lengths 17, 18, 19, 20 of the spring steel sheet strips 2 have a shape, such as si 1, the shape of the spring elements 23 in the preferred embodiment of the invention is largely similar to this. The substantially diamond-shaped head part of the spring element 23 lies within the box-shaped part of the corner piece 16 and only touches the inner surface of the corner piece 16 in a linear manner with one corner in the region of the curvature 25 and is spaced apart from the inner surface. At the head part of the spring element 23 is a foot part, which is formed from parallel side surfaces 22, the distance between which is dimensioned such that the edge surfaces 21 of the corner piece 16 on the

Lateral surfaces 22 lie loosely and in this way sliding surfaces for a linear displacement of the corner piece 16 are created. The side surfaces 22 are formed in their lower part as a clamping edge and can be fastened in the same way as the sealing arrangement according to FIG. 1 by means of screws, clamping pieces and an inserted hollow profile In the present case, this is realized by means of L-shaped holding profiles 13. The shape and dimensions of the spring element 23 are largely the same as those of the spring steel sheet strip 2 or come very close to them, with the exception that the side faces 22 are significantly lengthened compared to the corresponding faces which merely act as tensioning edges 3 are to create the sliding surfaces in the foot part, as can be seen in FIG. 2 but cannot be seen in FIG. 3, the end faces of the corner pieces 16 are provided with end plates 24, the latter being able to be of flat design, but can also be inscribed on the edge area of the corner piece 16 nken sense of these end plates 24 is that they form a clean contact surface for the loosely connected partial lengths 17, 18, 19, 20 of the spring steel sheet strip 2, so that sliding on it is possible if necessary The function of the sealing device according to the invention is as follows: the individual partial lengths of the spring steel sheet strip 2, which are not shown in any more detail, are axially flush with one another, as are the partial lengths 17, 18, 19, 20 and the legs of the corner pieces 16. The open end faces of the partial lengths 17,

18, 19, 20 each on an end plate 24 of the corner piece 16 in such a way that the end faces are completely covered by the end plates 24. The alignment is such that the linear sealing zone 4 in the unloaded state is flush with the curvature 25 of the corner pieces 16, so that overall there is a continuous narrow contact surface for the counter surface of the sealing seat, which has no height offset. For this purpose, it is of course necessary that the holding profiles with which the partial lengths 17, 18, 19, 20 are attached, because of the foot parts of the spring steel sheet strips 2 formed only as a clamping edge 3, have correspondingly different dimensions than the holding profiles 13 for the much higher foot parts of the Spring elements 23 of the corner pieces 16. Since the

Because of their resilient support on the spring elements 23 under the action of a sealing force, corner pieces 16 can retreat in the same way as the spring steel sheet strips 2, even in the loaded state, a contact surface for the counter surface of the sealing seat that is free of vertical offset is ensured.

With the present invention, it is avoided that in the corner areas of a sealing device, for example as a result of strong thermal expansions, uneven deformations occur on the partial lengths of the spring steel sheet strip that collide in the corner area. Without the corner pieces according to the invention, an uneven deformation of the spring steel sheet strips would in each case lead to a gaping in the area of the joint and thus to a greater leak. However, this is avoided by the configuration of the sealing device according to the invention, the structural outlay for this being extraordinarily low. The spring stiffness of the entire sealing system is practically not affected. Due to the particularly simple construction, there is a high level of operational safety and reliability of the sealing system.

Claims

Claims:

1. Device for sealing the contact zone between two relatively movable system parts, one of which forms a shut-off element (1) and the other a sealing seat, containing at least one

Sealing element which is formed by a spring steel sheet strip (2) which extends along the contact zone and which is bent in the shape of a hollow profile, the sealing element in the closed position of the shut-off element with a sealing zone (4) which is convexly curved relative to the sealing seat, rests against the sealing seat by a spring force with a sealing force and the hollow profile-shaped spring steel sheet strip (2) is made up of partial lengths (17, 18, 19, 20) to form a closed polygon, characterized in that

- That the corners of the polygon are filled with hollow profile-shaped corner pieces (16) which have a practically rigid outer shape with respect to the action of the sealing force,

- That the corner pieces are mounted on a resilient support in the direction of the sealing force,

- That the corner pieces (16) are each provided with a flat end plate, which is arranged parallel to the direction of the sealing force and perpendicular to the longitudinal axis of the subsequent partial length (17, 18, 19, 20) of the hollow profile spring steel sheet strip (2) and

- That each of a corner piece (16) adjoining partial length (17, 18, 19, 20) of the spring steel sheet strip (2), which is cut perpendicular to its longitudinal axis, lies closely with its end face on the respective end plate (24), in particular slidably is present.

2. Device according to claim 1, characterized in that the resilient support is formed by a spring element (23) which is arranged within the hollow profile-shaped corner piece (16) and at least selectively abuts the inner surface of the corner piece (16).

3. Device according to one of claims 1 to 2, characterized in that that the spring element (23) is designed as an open hollow profile with a cross-sectionally substantially diamond-shaped head part and a foot part connected to it, which is formed by the side surfaces (22) of the hollow profile which run parallel and at a distance from one another.

4. The device according to claim 3, characterized in that side surfaces (22) form at their lower end clamping edges for fastening the spring element (23).

5. The device according to claim 4, characterized in that the side surfaces (22) form sliding surfaces for the mutually parallel edge surfaces (21) of the hollow profile-shaped corner piece (16).

6. Device according to one of claims 2 to 5, characterized in that the spring element (23) has a substantially the shape of the spring steel sheet strip (2) corresponding shape and also consists of spring steel.

7. Device according to one of claims 1 to 6, characterized in that the resilient support has a spring characteristic which corresponds at least approximately to the spring characteristic of the spring steel sheet strip (2).

8. Device according to one of claims 2 to 7, characterized in that the corner piece (16) has a significantly greater wall thickness than that

Spring steel sheet strip (2), in particular a wall thickness twice to five times larger.

9. Device according to one of claims 2 to 8, characterized in that the corner piece (16) is composed as a welded construction made of miter cut hollow profile individual pieces.

10. Device according to one of claims 1 to 9, characterized in that the corner piece (16) has a substantially box-shaped basic shape in cross section, the surface on which the counter surfaces of the sealing seat comes to rest in the unloaded state of the device for training a linear sealing zone (25) is curved outwards.