DE102010019864A1 - Clamp for pipe connections - Google Patents

Abstract

The invention relates to a clamp with an outer and an inner side, in particular for non-positive connection of plastic pipes (1, 2) or hoses, with a pipe to be connected (1) over a majority of its circumference surrounding, preferably made of sheet metal clamp band (4th ). The end portions of the clamp band (4) are formed as against the inside of the clamp bent loops (4a, 4b) with free ends (4e, 4f). The free ends (4e, 4f) of the loops (4a, 4b) are connected to the circumference of the clamp band (4) at at least one connection point (4c, 4d). The free end (4e, 4f) of the loop projects beyond the connection point (4c, 4d) by at least 5% of the circumference.

Description

The The invention relates to a clamp with an outside and an inside, in particular for frictional connection of plastic pipes or hoses, with one to be connected Pipe surrounding a large part of its circumference, preferably made of sheet metal clamp band whose end portions as against the inside of the clamp bent loops with free ends are formed, wherein the free ends of the loops at least a connection point connected to the circumference of the clamp band are.

For non-positive connection of plastic pipes, a variety of different pipe joints are known and are also applied. For example, from the EP 0 205 896 B1 a pipe coupling is known, which has a metallic housing and arranged therein, in cross-section C-shaped sealing collar. Toothed anchoring rings are axially and radially supported by plate-like disks in the corner of the housing. When clamping the housing on the one hand, the sealing lips of the sealing sleeve are pressed against the lateral surface of the plastic pipes and on the other hand penetrate the teeth of the anchoring elements in this lateral surface of the plastic pipes. Thus, on the one hand the pipes are sealed and on the other hand achieved a tensile connection of the pipes. However, these pipe couplings are relatively complex and limited on the other hand in the diameter range of the plastic pipes. In order to avoid a collapse of the plastic pipes by the bracing, metallic support rings are inserted into the pipe ends.

The EP 1 141 607 B1 shows a pipe joint for plastic pipes, in which the plastic pipes are pressed by introducing a fluid introduced into a sleeve surrounding the pipe radially inwardly against a connecting the pipes together, inserted into the pipe ends coupling sleeve. However, this solution is very complex, by requiring technical aids such as pumps and the like. To apply the pressure in the fluid.

Instead of the cuffs have also been tried, the pipes by means of clamp bands to press radially against the coupling sleeves. Because of the high occurring Forces are relatively high material thicknesses required to use the clamp bands. Because such Pipe connections very often the weather and / or corrosive atmosphere are exposed, for reasons of corrosion protection These clamp bands usually made of stainless (chromium-nickel) steel produced. The material costs are therefore very high. Moreover there is a risk of crevice corrosion when fixing the loop ends, especially with welded joints.

From the DE 100 48 955 A1 a clamp band is known in which the ends of the loops are bent inwardly and secured by radially outwardly projecting, passed through slots and bent tabs. Instead of the lobes can also serve cup-shaped projections for connection, which are positively inserted into a hole of the opposite region. All of these connections must absorb virtually all of the tangential biasing forces.

The WO 2007/060563 shows a clamp or pipe clamp, in which the loops are just bent against the inside and the free ends of the loops are secured by positive (press / join) connections. Even with this solution, these compounds need to absorb virtually all of the biasing forces.

From the US 2008/0040897 A1 Clamps for round or square objects are known in which the loops are also bent inwards. The attachment of the loops is compared to the free end of the loops something set back (by about 12 ° or about 3% of the circumference). This should mean an improvement over the mentioned in this document and illustrated also prior art with bent-out tabs an improvement. When overloading the tab by tensile forces occurring during operation, the junction at the free ends of the tab is not torn as in the prior art, or sheared off, but the inside of the tab is pressed radially against the object to be clamped.

Of the Invention has for its object to provide a clamp, the application of high clamping forces with low material thickness allows.

According to the invention, this is achieved in that the free end of the Loop overhangs the joint by at least 5% of the circumference. When tightening the clamp band this becomes the connection point circumferentially superior area, as by the way also the area of the clamp band between the loops, radial pressed against the pipe. As a result of static friction with the lateral surface of the tube, this can be superior to the junction Take over part of the tensile forces occurring at the tab. This leads to a considerable relief of the connection point the tabs.

Another improvement and optimization the force relationships is achieved in that the free end of the loop extends beyond the junction by about 10% of the circumference. By relieving the junction of the tabs, it is possible to get along with a minimum thickness of the clamp band.

The Junction is preferably as positive connections educated. Positive connections give against welded joints (eg spot welding or seam welding) have considerable advantages concerning corrosion resistance.

A particularly expedient solution is that the joint as press / join connections ("clinching") is trained. Allow such press / joint connections in particular very high shear forces.

The Pressing / joining connections are advantageous as circular Holes in the clamp band and cup-shaped, form-fitting engaging in the holes in the end region of the loops Formed forms. Due to the circular shape of the holes, or the positively engaging in these forms the notch risk is relatively low.

ever according to the size of the bracing, or during operation of the Piping forces, it is expedient a plurality of joints arranged side by side in the axial direction provided. Due to the number of joints, the safety factor determined, or defined.

Around a uniform distribution of forces over To reach the entire tube circumference, it is advantageous on the directed against the pipes to be connected inside the loops a bridging the gap between the loops To arrange insert. This insert expediently extends from the junction of the one loop to the junction the other, opposite loop.

Plastic pipes have relative to occurring pressure from the outside a relative low stability. To a squeezing To avoid, therefore, is beneficial on an inside of the connecting plastic pipes or hoses arranged a support sleeve. This support sleeve also forms the connection sleeve the two plastic pipes to be joined together.

Around when bracing the pipes a good connection of the plastic pipes to reach with the support sleeve is the support sleeve on its outside conveniently with profilings Mistake. Such profiles allow a form-fitting Engage and prevent "slipping" of the pipes.

The Profiles are advantageously designed as embossments. Such imprints can be used as an example Teeth or scales are formed.

There the support sleeves in most cases are produced as turned parts, it is appropriate that the profiles are designed as circumferential ribs.

The Support sleeve should be joined together at both Plastic pipes are introduced the same depth. To this to ensure and facilitate the application is it is expedient that the support sleeve in their central area has a circumferential collar. This The collar serves to insert the support sleeve as an axial stop.

At the Mounting process, it is advantageous that a support sleeve about half of its length in the free end a first tube to be connected is inserted and the first tube axially superior area of the support sleeve in the free end of a second, to be connected to the first tube Tube is inserted and then two clamps after one the aforementioned embodiments via the pipe ends pushed and tightened.

Further Embodiments of the invention are shown in the figures and in the dependent Claims specified.

The Reference numerals are part of the disclosure.

Based of figures, the invention is explained in more detail by way of example. The figures become coherent and comprehensive described. The same reference numerals mean the same components, reference numerals with different indices give functionally identical or similar Components on.

It demonstrate:

1 A pipe joint with an inventive clamp, partially in longitudinal section,

2 a cross section through the in 1 illustrated pipe joint, along the line II-II,

3 the clamp band of a clamp, accordingly 2 on an enlarged scale,

4 a bell band accordingly 3 , in perspective,

5 another embodiment of a clamp, with one piece trained clamp band.

Out 1 are two plastic pipes 1 . 2 which can be seen by means of two clamp bands according to the invention 3 . 4 connected to each other tensile strength. The illustrated clamp bands 3 . 4 are identical.

As from the in 2 illustrated cross-section of the clamp band 3 respectively. 4 shows, the clamp band 3 respectively. 4 at its ends two loops bent against the inside 3a . 3b respectively. 4a . 4b on. In the area of the overlap of the loops 3a . 3b respectively. 4a . 4b are connection points 3c . 3d respectively. 4c . 4d arranged. The connection points 3c . 3d respectively. 4c . 4d are preferably formed without sweat as press / Fügevebindungen. In technical terms, this type of connection is also known neutrally as "clinching" or with the brand name "toxen". In one part, preferably circular holes are punched out and punched out in the other part pot-shaped elevation, which are then pressed positively into the holes during connection. This type of compound is distinguished from welded joints in particular by a very high corrosion resistance. The free ends 3e . 3f respectively. 4e . 4f surmount the joints 3c . 3d respectively. 4c . 4d about 10% of the circumference, ie around a circular arc angle of about 30 °. This will ensure that the joint is due to the stiction between the inside of the loop 3a . 3b respectively. 4a . 4b and the pipe to be connected 1 respectively. 2 is substantially relieved.

In the loops 3a . 4a are punch bolts 5 and in the loops 3b . 4b are threaded bolts 6 used. By means of a hole bolt 5 and the threaded bolt 6 connecting screw plug 7 can the clamp bands 3 . 4 over the circumference of the plastic pipes 1 . 2 be tense. The clamp bands 3 . 4 are in the range of loops 3a . 3b ; 4a . 4b with slits 3g . 4g provided, which the passage of the threaded shank of the screw plug 7 or the screw head serve. Between the two loops 3a . 3b ; 4a . 4b there is a gap 3h respectively. 4h , which by a preferably consisting of a steel strip insert 9 is bridged. The deposit 9 extends over both joints 3c . 3d , respectively. 4c . 4d and is preferably at one end, for example. By a spot welding with the clamp band 3 respectively. 4 attached.

As in particular from the in 1 shown longitudinal section through the pipe connection is a support sleeve 8th in the free ends of the plastic pipes 1 . 2 used. The support sleeve 8th has several functions. On the one hand, it seals the pipe gap between the two plastic pipes 1 . 2 from. In addition, the support sleeve prevents collapse of the plastic pipes 1 . 2 when tightening the clamp bands 3 . 4 , At its cylindrical end regions is the support sleeve with profilings 8a , z. B. ribs or the like. Provided. When tightening the clamp bands 3 . 4 these are profiling 8a pressed into the tube inner wall and thus allow an axial frictional connection between the plastic pipes 1 . 2 , The illustrated support sleeve ( 8th ) has in its central region a circumferential collar ( 8b ) on.

In the opposite of the 2 enlarged representation of the clamp band 3 in 3 are the free ends 3e . 3f , which connection points 3c . 3d clearly surmounted by the angle α in the circumference. The angle α is preferably about 30 °, ie the free ends 3e . 3f , which protrude beyond the connection points, extend over about 1/10 of the circumference. As in particular from the perspective view of a clamp band 4 in 4 There are several connection points 4d , viewed in the axial direction, arranged side by side. The number of connection points 4d depends on the width of the clamp band 4 or after the load occurring during operation.

The out 5 apparent longitudinal section through a further embodiment of an inventive clamp also shows two plastic pipes 11 . 12 , which by means of a inserted into the pipe ends support sleeve 18 connected to each other. Between the two spaced plastic pipes 11 . 12 there is a pipe burst 10 , The support sleeve 18 is at its cylindrical end areas with profilings 18a provided and has in its central region also a covenant 18b on when inserting the support sleeve 18 in the ends of the plastic pipes 11 . 12 serves as an axial stop.

Unlike the in 1 illustrated embodiment, in which two separate clamp bands 3 . 4 over the plastic pipes 1 . 2 be tense, are in 5 The two clamp bands together as a one-piece clamp band 13 educated. The clamp band 13 is about the same width as the total length of the support sleeve 18 , Because of the clamp 13 also the pipe joint 10 between the plastic pipes 11 . 12 Covering the outside, on the one hand prevents pollution from the outside into the pipe joint 10 penetrate and on the other hand into the pipe wall of the plastic pipes 11 . 12 Diffusing medium of the pipe at the front of the plastic pipes 11 . 12 can escape.

1

Plastic pipe

2

Plastic pipe

3

clamp band

3a

loop

3b

loop

3c

junction

3d

junction

3e

free The End

3f

free The End

3g

slot

3h

gap

4

clamp band

4a

loop

4b

loop

4c

junction

4d

junction

4e

free The End

4f

free The End

4g

slot

4h

gap

5

holepin

6

threaded bolt

7

Screw

8th

support sleeve

8a

profiling

8b

Federation

9

inlay

10

tube shock

11

Plastic tube

12

Plastic tube

13

clamp band

18

support sleeve

18a

profiling

18b

Federation

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0205896 B1 [0002]
• - EP 1141607 B1 [0003]
• DE 10048955 A1 [0005]
• - WO 2007/060563 [0006]
• US 2008/0040897 A1 [0007]

Claims (15)

Clamp with an outer and an inner side, in particular for non-positive connection of plastic pipes ( 1 . 2 . 11 . 12 ) or hoses, with a pipe to be connected ( 1 . 2 ; 11 . 12 ) over a majority of its circumference surrounding, preferably made of sheet metal clamp band ( 3 . 4 ; 13 ), whose end regions ( 3e . 3f ; 4e . 4f ) as against the inside of the clamp bent loops ( 3a . 3b ; 4a . 4b ) with free ends ( 3e . 3f ; 4e . 4f ) are formed, wherein the free ends ( 3e . 3f ; 4e . 4f ) of the loops ( 3a . 3b ; 4a . 4b ) at at least one connection point ( 3c . 3d ; 4c . 4d ) with the circumference of the clamp band ( 3 . 4 ), characterized in that the free end ( 3e . 3f ; 4e . 4f ) of the loop ( 3a . 3b ; 4a . 4b ) the connection point ( 3c . 3d ; 4c . 4d ) surpasses at least 5% of the circumference. Clamping clamp according to claim 1, characterized in that the free end ( 3e . 3f ; 4e . 4f ) of the loop ( 3a . 3b ; 4a . 4b ) the connection point ( 3c . 3d ; 4c . 4d ) surmounted by about 10% of the circumference. Clamping clamp according to claim 1 or 2, characterized in that the connection point ( 3c . 3d ; 4c . 4d ) is designed as positive connections. Clamping clamp according to claim 3, characterized in that the connection point ( 3c . 3d ; 4c . 4d ) is designed as a press / joining connections ("clinching"). Clamping clamp according to claim 4, characterized that the press / joint connections as circular holes in the clamp band and cup-shaped, form-fitting engaging in the holes in the end region of the loops From embossments are formed. Clamping clamp according to one of claims 3 to 5, characterized in that a plurality of juxtaposed in the axial direction of connection points ( 3c . 3d ; 4c . 4d ) are provided. Clamping clamp according to one of the preceding claims, characterized in that on the directed against the pipes to be connected inside the loops ( 3a . 3b ; 4a . 4b ) a gap ( 3h . 4h ) between the loops ( 3a . 3b ; 4a . 4b ) bridging deposit ( 9 ) is arranged. Clamp according to claim 7, characterized in that the insert ( 9 ) from the junction ( 3c . 4c ,) of a loop ( 3a . 4a ) to the junction ( 3d . 4d ) of the other, opposite loop ( 3b . 4b ). Clamping clamp according to one of the preceding claims, characterized in that on an inner side of the plastic pipes to be connected ( 1 . 2 ) or hoses a support sleeve ( 8th ) is arranged Clamping clamp according to claim 9, characterized in that the support sleeve ( 8th ) on its outside profiles ( 8a ) having. Clamping clamp according to claim 10, characterized in that the profilings ( 8a ) are formed as embossments Clamping clamp according to claim 10, characterized in that the profilings ( 8a ) are designed as circumferential ribs. Clamping clamp according to one of claims 9 to 12, characterized in that the support sleeve ( 8th ) in its central region a circumferential collar ( 8b ) having. Clamping clamp according to one of the preceding claims, characterized in that the clamp band ( 13 ) via a pipe joint ( 10 ) as well as the pipe joint ( 10 ) adjacent ends of the plastic tubes ( 11 . 12 ). Method for connecting pipes with a clamp according to one of the preceding claims, characterized in that a support sleeve ( 8th . 18 ) about half of its length in the free end of a first pipe to be connected ( 1 . 11 ) and the first tube ( 1 . 11 ) axially projecting portion of the support sleeve ( 8th . 18 ) in the free end of a second pipe to be connected to the first pipe ( 2 . 12 ) and then one or two clamp bands ( 3 . 4 ; 13 ) according to one of the preceding claims, over the ends of the tubes ( 1 . 2 ; 11 . 12 ) and tightened.