DE102009035040A1 - Method for continuous production of pipe from thermoplastic material in production direction, involves outwardly applying partial vacuum on tube during production of ring-shaped corrugation in region of trailing flank and/or base portion - Google Patents

Abstract

The method involves connecting leading- and trailing flanks by an outer ring-shaped peripheral wall, and extruding a tube in a production direction (6). The tube is provided with a ring-shaped corrugation by an outwardly applied partial vacuum and inwardly applied pressure. The partial vacuum is applied in a region of the peripheral wall to be produced. The partial vacuum is outwardly applied on the tube during production of the corrugation in a region of a trailing flank and/or a base portion. A vacuum opening is formed on a side-flank. An independent claim is also included for a device for continuous production of a pipe from a thermoplastic material in a production direction.

Description

The The invention relates to a process for the continuous production of a Pipe according to the preamble of claim 1 and a device to carry out the method according to the preamble of Claim 8.

The method and the device of the generic type are for example from EP 0 563 575 B1 (Corr. U.S. Patent 5,320,797 ) known. Vacuum deposition through the vacuum slots in the outer wall sections of the mold has resulted in satisfactorily molding the corrugations of both simple corrugated pipes and composite pipes, ie pipes consisting of a smooth inner pipe and a corrugated outer pipe welded thereto ,

In Practice has shown that with large pipe diameters with correspondingly larger corrugations shaping the curl was no longer satisfactory.

Of the The invention is therefore based on the object, a method of the generic type Art, by means of which even with larger pipe diameters Curl is formed satisfactorily, and a device to carry out the procedure.

These Task is in a method of the generic Type by the features in the characterizing part of claim 1 and in a device of the generic type solved by the features in the characterizing part of claim 8. The essence of the invention is that by exercise also a partial vacuum at least on - based on the Production direction - trailing edge of a corrugation is achieved that these not only molded, but also during the cooling process is held. The exercise of such a partial vacuum on the - in relation to the production direction - leading Flank of a corrugation is possible, but not necessary. Alternatively or cumulatively, the additional part vacuum also on the foot section, namely the lagging foot section a curl be exercised. By the invention On the one hand, measures are taken to shape the corrugation during the time course of the formation of the corrugation a uniform vacuum force over the entire cross section of the corrugation exerted on the tube. After the formation of the corrugation becomes an additional holding force exerted on the hose, reducing the contact time between extended to the plastic and the metallic wall of the mold becomes. This increases the heat dissipation, resulting in a geometry of the corrugation with very low tolerances leads.

The dependent claims give advantageous embodiments again.

Further Features, advantages and details of the invention will become apparent the following description of an embodiment based on the drawing. It shows

1 a device for producing tubes in plan view,

2 an end view of the device according to the viewing arrow II in 1 .

3 a vertical cross section through two joined to a mold section mold section halves,

4 a partial longitudinal sectional view of a mold section half and

5 a cross section through the mold section half corresponding to the section line VV in 4 ,

The 1 and 2 show an apparatus for producing pipes of thermoplastic material with transverse profiling. This device has a base plate 1 on top of which is a shape track 2 located. On this shape track 2 become mold sections 3 strung together, each consisting of two section halves 4 . 5 consist. As long as the mold section halves 4 . 5 in pairs, forming a mold section 3 abut each other and as long as adjacent mold sections 3 to form a shape abut each other, they move in a straight line according to a production direction 6 on the base plate 1 , For continuous drive through the mold sections 3 Form formed is immediately behind a spray head 7 an extruder, a lower drive pinion 8th provided by a recess 9 in the base plate 1 protrudes and in a on the respective underside of the mold section halves 4 . 5 trained tooth profile 10 intervenes. The lower drive pinion 8th is non-rotatable on a drive shaft 11 attached, the below the base plate 1 is stored and is driven by a gear motor, not shown. The form section halves 4 . 5 be on the shape range 2 each with guide rails 12 . 13 guided or held together in the base plate 1 adjacent area of the mold section halves 4 . 5 attack at this.

Above the base plate and above the mold is an abutment 14 intended. This has a base plate 15 on top of which is an upper drive pinion 16 is stored. This upper drive pinion 16 is also rotationally fixed to a drive shaft 17 attached, the two sides in camps 18 . 19 is stored, the on the base plate 15 are attached. The drive shaft 17 is powered by a transmission engine 20 driven on the neighboring camp 18 is appropriate. At the bottom of the base plate 15 are support rollers 21 with horizontal axis of rotation 22 Stored, located on top of each mold section half 4 . 5 trained support surfaces 23 support, reducing the location of the counter bearing 14 to the mold section halves 4 is defined. At the bottom of the base plate 15 continue to be leadership roles 24 with vertical axis of rotation 25 stored, the side of guide surfaces 26 attack, which is also at the top of the mold section halves 4 . 5 are formed. By means of these guide rollers 24 two become a form section 3 forming mold section halves 4 . 5 guided in their upper area or held together. The upper drive pinion 16 engages between the support surfaces 23 or the guide surfaces 26 in a tooth profile 27 one at the tops of the mold section halves 4 . 5 is trained. Over the upper drive pinion 16 Only 1/3 to 1/4 of the amount of feed force on the mold sections 3 transmitted through the lower drive pinion 8th on the mold sections 3 is exercised. The counter bearing 14 is in on the base plate 1 mounted vertically from this upstanding torque arms 28 supported by the transmission engine 20 on the counter bearing 14 absorb applied torque. The counter bearing 14 itself is essentially due to its own weight on the support surfaces 23 on. This dead weight is also sufficient, the engagement of the upper drive pinion 16 in the tooth profile 27 occurring, vertically upwards on the counter bearing 14 to compensate for acting forces.

Above the base plate 1 is a transport device 29 for the mold section halves 4 . 5 intended. This transport device 29 is constructed in the manner of a bridge crane. It has two parallel to the transport direction 6 , to the central longitudinal axis 30 the mold sections 3 and to the base plate 1 and mutually parallel guide rails 31 . 32 on. These are above the counter bearing 14 arranged and supported 33 opposite the base plate 1 supported. On the guide rails 31 . 32 is a transport bridge 34 over run cart 35 supported. The displacement of the transport bridge 34 on the guide rails 31 . 32 done by means of linear drives 36 , which are formed in the specific embodiment as a spindle drives. These linear drives 36 accordingly, on the guide rails 31 . 32 arranged threaded spindles 37 on which threaded nuts 38 are arranged, in turn, to the barrel wagon 35 are attached. The threaded spindles 37 are each via a transmission engine 39 . 40 driven, these two gear motors 39 . 40 over a horizontal and transverse to the guide rails 31 . 32 extending dome wave 41 are positively synchronized. The two threaded spindles 37 So are driven exactly the same speed, so that the transport bridge 34 tilt-free on the guide rails 31 . 32 is moved. The transport bridge 34 has two bridge sections 42 . 43 on, each from the guide rails 31 . 32 Seen from each other to the base plate 1 run inclined. The distance of the bridge 34 from the base plate 1 is thus in its center, vertically above the central longitudinal axis 30 least. On the two bridge sections 42 . 43 is a transport cart 44 . 45 movably arranged, in the respective direction of travel 46 respectively. 47 by means of a linear drive 48 respectively. 49 is displaceable. These linear drives 48 . 49 essentially consist of one in each bridge section 42 respectively. 43 mounted threaded spindle 50 in a threaded nut 51 at the respective transport car 44 respectively. 45 intervenes. The two threaded spindles 50 be from a common transmission engine 52 driven. The geared motors 39 . 40 and the gearbox engine 52 are reversible motors, so suitable for forward and reverse.

At the transport cart 44 and 45 is each a transport arm 53 attached, which extends vertically downwards. At every transport arm 53 is a holding device 54 for a form section half 4 respectively. 5 appropriate. It is assigned to each section of the form section 4 respectively. 5 a holding abutment 55 educated. Every holding device 54 has an upper attachment 56 on, against the bottom of a holding abutment 55 is pressed. To the holding device 54 still includes a tensioning device 57 consisting essentially of a pneumatic or hydraulic piston-cylinder drive 58 consists. At the piston rod 59 this drive 58 is a locking pin 60 formed, the corresponding actuation of the drive 58 in a locking recess 61 at the bottom of the retaining abutment 55 engages and at the same time the abutment 55 against the plant 56 suppressed. In the in 2 shown on the left is the holding device 54 firmly with the retaining abutment 55 the adjacent form section half 4 respectively. 5 locked; the latter is thus fixed to the transport arm 53 connected.

At the guide rails 31 . 32 are proximity switches 62 . 63 . 63a . 64 arranged when approaching the transport bridge 34 Deliver their position representative signals to a central control unit, which is not shown. At the transport bridge 34 are also proximity switches 65 . 66 attached, which is an inner or an outer position of the respective transport carriage 44 . 45 emit representative signals to the central control unit.

The previously described device is from the EP 0 764 516 B1 (Corr. U.S. Patent 5,693,347 ) known.

In the area of the form track 2 are in the base plate 1 connected to one or more vacuum pumps, not shown, to the mold section halves 4 . 5 open vacuum connections 67 . 68 educated. These are several in each form section half 4 . 5 trained vacuum channels 69 . 70 assigned, each with the vacuum connections 67 . 68 come in coincidence when the mold section halves 4 . 5 to a molding section 3 on the shape track 2 are merged.

The form section halves 4 . 5 point in to a molding section 3 composite state a hollow shape space 71 on, the boundary wall by short approximately cylindrical wall sections 72 and from these inward to the axis 30 directed form webs 73 is formed, which alternate each other. The annular shaped webs 73 each have a wall section 72 inclined web flanks 74 . 75 on, wherein the inclination is such that the respective molding web 73 adjacent to the wall section 72 a greater thickness in the direction of the axis 30 than on its inner axis 30 facing peripheral surface 76 , The form bars 73 so rejuvenate towards the axis 30 out.

To the shape space 71 around are parallel to the axis 30 extending, sealed at their ends vacuum connection channels 77 in the form section halves 4 . 5 formed the vacuum channels 69 . 70 penetrate. The vacuum channels 69 . 70 surround the shape space 71 in particular 3 is removable. In the wall sections 72 are vacuum slots 78 formed the vacuum channels 69 . 70 with the shape space 71 in the area of the respective wall sections 72 connect.

In the form of webs 73 are distributed over the circumference vacuum openings 79 trained, at least in the direction of production 6 leading bridge flank 74 of the respective form bar 73 , The respective vacuum openings 79 can, for example, via vacuum bores 80 . 81 with the respective vacuum connection channels 77 be connected, the vacuum holes 80 opposite the mold space 71 by means of sealing plugs 82 are closed. The vacuum openings 79 have sieve-like plugs 84 . 83 on, prevent the penetration of warm plastic plastic, but not affect the effect of the partial vacuum. Under sieve-like is to be understood that the plugs 84 . 83 have either holes or slots. The on the - related to the production direction 6 - trailing edge 75 arranged sieve-like plug 83 can also be replaced by sealing plugs, so that there is no partial vacuum exerted.

In the vacuum connection channels 77 are each - related to the production direction 6 - behind the mouth of the radial to the axis 30 running vacuum hole 80 from the corresponding vacuum connection channel 77 sealing plug 85 provided so that each one wall section 72 and one in production direction 6 lagging bridge flank 74 one or two vacuum channels 69 . 70 assigned. About the circumference of the mold space 71 are so many vacuum connection channels 77 arranged, such as vacuum openings 79 on every bridge flank 74 or on each mold bridge 73 are provided. In the present case are six vacuum connection channels 77 in each shape section half 4 . 5 formed, which are arranged at equal angular intervals of 20 ° to 45 ° and preferably 30 °. Through the described assignment of the vacuum connection channel sections 77a . 77b . 77c . 77d to the individual bridge flanks 74 or form bars 73 and wall sections 72 It is possible by appropriate division of the vacuum connections 67 . 68 in the base plate 1 each almost identical vacuum conditions in each wall section 72 to accomplish.

The mode of action is as follows:
From the spray head 7 The extruder will be two hoses, namely an inner tube 88 and an outer tube 89 , extruded from warm plastic, which is at the upstream end 86 the shape track 2 enter the mold and there by means of vacuum and possibly support air to a composite pipe 87 be deformed, which has a smooth inner tube and a corrugated outer tube, as in detail from the EP 0 563 575 B1 (Corr. U.S. Patent 5,320,797 ) is known, to which reference may be made. Instead of a composite pipe 87 can also be made from just a hose made of plastic plastic a corrugated tube, as is known from the EP 0 065 729 B1 (Corr. U.S. Patent 4,492,551 ) is known. Furthermore, only a finned tube can be made, as it is known from EP 0 301 189 B1 (Corr. U.S. Patent 4,900,503 ) is known.

The from the mold sections 3 existing form migrates in the direction of production 6 in front. The tube created in it 87 moves with the same speed. Whenever a molding section 3 the downstream end 90 the shape track 2 has achieved, the two have this form section 3 forming mold section halves 4 . 5 across the production line 6 from the shape line 2 be taken out. This happens - as in 1 and 2 shown by dashed lines - by means of the transport car 44 . 45 with transport arms 53 ge formed cross conveyors. The transport bridge 34 becomes during the last short distance of the in production direction 6 last form section 3 co-speeded with this, with the two transport cars 44 . 45 were moved to their adjacent position. In this position are the holding devices 54 with the holding abutments 55 the two mold section halves 4 . 5 locked. Upon reaching the downstream end 90 become the two transport carriages 44 . 45 due to a corresponding signal of the proximity switch 63 apart, including the transmission engine 52 is controlled accordingly. Due to the inclination of the two bridge sections 42 . 43 become those at the transport arms 53 held form section halves 4 . 5 from the base plate 1 lifted and smoothly moved outward. If the transport car 44 . 45 the outer proximity switches 66 they are stopped. The geared motors 39 . 40 are driven, so the transport bridge 34 contrary to the direction of production 6 to the upstream end 86 the shape track 2 is moved. Also in this transport of the mold section halves 4 . 5 contrary to the direction of production 6 these are not in contact with the base plate 1 but are located above this without friction. They are always moved in parallel to themselves.

Upon reaching the upstream proximity switch 62 become the gearbox engines 39 . 40 stopped, so the transport bridge 34 stationary. It will, however, the transmission engine 52 switched on and moves the transport car 44 . 45 inwardly toward the molding path and guides the two mold section halves 4 . 5 at the upstream end 86 across the production line 6 into the shape range 2 a, like in 1 and 2 is shown pulled out. When moving the transport cart 44 . 45 to the shape range 2 due to the inclination of the bridge sections 42 . 43 the mold section halves 4 . 5 back to the base plate 1 lowered down on which they come to rest when the two mold section halves 4 . 5 a mold section 3 Touch each other as it is in 2 is shown. Subsequently, the transport bridge 34 in production direction 6 proceed until the two already have a molding section 3 forming mold section halves 4 . 5 at the in production direction 6 leading mold section halves 4 . 5 come to the plant and from the drive pinions 8th and 16 recorded and further promoted. Then the clamping devices 57 solved and the transport arms 53 each again moved away from the molding path to the outside. The transport bridge 34 is then back to the downstream end 90 method, as previously described.

For forming the corrugated outer tube from the outer tube 89 are the vacuum slots 78 With vacuum applied, it should be pointed out that when it comes to vacuum, of course, only a partial vacuum is meant, so a pressure below atmospheric pressure. Through this part-vacuum at the vacuum slots 78 and the higher pressure in the outer tube 89 becomes the outer tube forming the corrugated outer tube 89 outwards to the corresponding wall section 72 pressed. This outer tube 89 attaches itself to the in production direction 6 lagging bridge flank 75 of the respective wall section 72 leading mold bridge 73 and to the wall section 72 at. Because of the vacuum openings 79 in - in relation to the production direction 6 - leading bridge flanks 74 the - related to each wall section 72 trailing ridges 73 in the area of the inner peripheral surface 76 are subjected to partial vacuum, sets the outer tube 89 also to the corresponding leading edge 74 of the wall section 72 lagging formbridge 73 , A curl 91 of the outer tube 89 therefore has one - in relation to the production direction 6 - leading edge 92 on, on the trailing edge 75 a formbridge 73 is applied. It also has one - in terms of production direction 6 - trailing edge 93 on that at the corresponding leading edge 74 the next mold bridge 73 is applied. It also has an outer annular peripheral wall 94 on which the two flanks 92 . 93 combines. In addition, it has a leading and trailing foot section, respectively 95 on, at the respective inner peripheral surface 76 is trained. These foot sections 95 be with the inner tube 88 welded, resulting in the composite tube after solidification 87 is formed. In 4 is also strongly indicated schematically as the inner tube 88 and the outer tube 89 be entered into the mold, and in particular as the outer tube 89 in the formation of the corrugation 91 to the lagging bridge flank 75 a leading mold bridge 73 and the wall section 72 abuts and like the outer tube 89 even before the bridge flank 74 against which he then by the vacuum at the vacuum slot 78 and at the vacuum opening 79 is created.

In 4 is also suggested that in the peripheral surface 76 a formbridge 73 one over the vacuum hole 80 with the vacuum channels 69 respectively. 70 connected, circumferentially extending slotted vacuum opening 96 can be trained. This slotted vacuum opening 96 can in addition to the vacuum openings 79 or alternatively be provided for this purpose.

In the formation of the corrugations 91 is usually in out of the EP 0 563 575 B1 (Corr. U.S. Patent 5,320,797 ) known blown slightly above atmospheric pressure support air. Together with the described partial vacuum, the forces on the outer tube 89 applied, which cause the curl 91 is formed clean and that the still warm plastic outer tube 89 taken with the migratory form and cooled.

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 0563575 B1 [0002, 0024, 0029]
• US 5320797 [0002, 0024, 0029]
• EP 0764516 B [0018]
• US 5693347 [0018]
• EP 0065729 B1 [0024]
• US 4492551 [0024]
• EP 0301189 B1 [0024]
• US 4900503 [0024]

Claims (15)

Method for the continuous production of a pipe ( 87 ) in a production direction ( 6 ), whereby the pipe ( 87 ) annular corrugations ( 91 ) which, in relation to the production direction ( 6 ) - one leading edge ( 92 ) and a trailing edge ( 93 ), one the two flanks ( 92 . 93 ) connecting outer annular peripheral wall ( 94 ) and inner foot sections ( 95 ), comprising the following steps: - a hose ( 89 ) in the production direction ( 6 extruded; - the hose ( 89 ) is by externally applied partial vacuum and internally applied pressure with the corrugations ( 91 ), wherein the partial vacuum in the region of the respective peripheral wall to be produced ( 94 ) is applied, characterized in that during the generation of each of the corrugations ( 91 ) also in the area of the trailing flanks ( 93 ) and / or the trailing foot sections ( 95 ) a partial vacuum from the outside on the hose ( 89 ) is applied. A method according to claim 1, characterized in that the partial vacuum on the trailing edges ( 93 ) distributed over the circumference is applied at discrete locations. Method according to claim 2, characterized in that that the discrete places are at an angular distance of 20 ° 45 ° from each other. A method according to claim 3, characterized in that the discrete points are at an angular distance of 30 ° from each other exhibit. Method according to one of claims 1 to 4, characterized in that the partial vacuum on the trailing edges ( 93 ) adjacent to the respective adjacent foot section ( 95 ) is applied. Method according to one of claims 1 to 5, characterized in that the partial vacuum also on the leading edge ( 92 ) is exercised. Method according to one of claims 1, 5, 6, characterized in that the partial vacuum over the circumference of at least one flank ( 92 . 93 ) and / or the respective foot section ( 95 ) from the outside onto the hose ( 89 ) is applied. Device for carrying out the method according to one of claims 1 to 7, - being located on a molding path ( 2 ) in pairs to one in a production direction ( 6 ) guided mold complementary mold section halves ( 4 . 5 ) on a machine frame ( 1 ) are arranged in the circuit, - wherein the shape of a mold space ( 71 ) with a central longitudinal axis ( 30 ), which by annular wall sections ( 72 ) and between each two adjacent wall sections ( 72 ) radially to the central longitudinal axis ( 30 ) projecting form webs ( 73 ), - the webs ( 73 ) - related to the production direction ( 6 ) - a leading bridge flank ( 74 ) and a trailing ridge flank ( 75 ) and one the bridge flanks ( 74 . 75 ) connecting inner peripheral surface ( 76 ), - wherein the annular wall sections ( 72 ) with vacuum slots ( 78 ) attached in the mold section halves ( 4 . 5 ) formed vacuum channels ( 69 . 70 ) are connected and - wherein the molding section ( 2 ) a spray head ( 7 ) for the extrusion of at least one tube into the molding space ( 71 ), characterized in that in the leading web flanks ( 74 ) and / or the peripheral surfaces ( 76 ) of the form webs ( 73 ) Vacuum openings ( 79 . 96 ) are formed, which with the vacuum channels ( 69 . 70 ) are connected. Apparatus according to claim 8, characterized in that the vacuum openings ( 79 ) are formed like a sieve. Apparatus according to claim 8 or 9, characterized in that the vacuum openings ( 96 ) are formed slit-like. Device according to one of claims 8 to 10, characterized in that the vacuum openings ( 79 . 96 ) by means of vacuum bores ( 80 . 81 ) with the vacuum channels ( 69 . 70 ) are connected. Apparatus according to claim 11, characterized in that the vacuum bores ( 80 . 81 ) by means of parallel to the central longitudinal axis ( 30 ) extending vacuum connection channels ( 77 ) with the vacuum channels ( 69 . 70 ) are connected. Apparatus according to claim 12, characterized in that the number of vacuum openings ( 79 ) in each mold bridge ( 73 ) equal to the number of vacuum connection channels ( 77 ). Apparatus according to claim 12, characterized in that the vacuum connection channels ( 77 ) into mutually sealed vacuum connection channel sections ( 77a . 77b . 77c . 77d ), wherein in each case a wall section ( 72 ) and the immediately following this form of web ( 73 ) a vacuum connection channel section ( 77a . 77b . 77c . 77d ) and that each vacuum connection channel section ( 77a . 77b . 77c . 77d ) to a vacuum channel ( 69 . 70 ) connected. Device according to one of claims 8 to 14, characterized in that also on the trailing ridge flank ( 75 ) Vacuum openings ( 79 ) are formed, which with the vacuum channels ( 69 . 70 ) are connected.

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