Flexible tubular moulded body, such as bellows, and method for the manufacture thereof

Abstract

The flexible tubular moulded body ( 10 ) comprises an unprofiled or profiled straight or bent shaped and a circumferential wall ( 11 ) provided with a corrugated profile ( 12 ), which is formed from a strength support insert embedded in a thermoplastic material comprising cord surfaces running in the longitudinal direction of the moulded body as pressure support elements and fixing threads running transversely to the threads and holding these in position.

1 . Method for producing a flexible tubular molded body, also arc, having a wall surface without or with a corrugated profile such as bellows, for air intake, turbo charging, cooling water and oil circuits and climatisation, for use in vehicle construction, ship building, mechanical engineering and aircraft construction, having at least one strength support insert which is embedded in a vulcanizable material, in an elastomer or in a thermoplastic, comprising the following steps:
 a) producing a surface structure by embedding a strength support insert or multiple superposed strength support inserts comprising threads or fibres or cord filaments running parallel to one another and at a distance from one another in the longitudinal direction to the axis of a cylindrical core tool having a corrugated profile on the outer side and/or with additional circumferential auxiliary threads wound in a helix manner and comprising fixing threads running transversely or diagonally to the threads or fibres or cord filaments running in the longitudinal direction and holding these in position in a vulcanizable material or in an elastomer or in a thermoplastic, where a section of the surface structure is applied to a cylindrical or hollow cylindrical core tool having a corrugated profile on the outer side and is deformed by means of a molding tool or press bandage, film, pressing rollers or profiles to form a bellows or   a1) producing, in an extrusion process, a tubular and strand-like molded body comprising one or multiple superposed strength support inserts embedded in a vulcanizable material or in an elastomer or in a thermoplastic comprising threads or fibres like cord filaments running in the longitudinal direction of the strand and at a distance from one another and/or with additional circumferential auxiliary threads wound in a helix manner and comprising fixing threads running transversely or diagonally to the threads or fibres or cord filaments running in the longitudinal direction and holding these in position and a subsequent shaping of the corrugated profile or arc of individual strand sections by means of sliding onto suitably shaped molding tools to produce individual bellows or shaped hoses including arcs.   
     
     
         2 . Method for producing a flexible tubular molded body, or arc, having a wall surface without or with a corrugated profile such as bellows, for air intake, turbo charging, cooling water and oil circuits and climatisation, for use in vehicle construction, ship building, mechanical engineering and aircraft construction, having at least one strength support insert which is embedded in a vulcanizable material, in an elastomer or in a thermoplastic, comprising the following steps:
 a) producing a surface structure by embedding a strength support insert or multiple superposed strength support inserts comprising threads or fibres or cord filaments running parallel to one another and at a distance from one another in the longitudinal direction to the axis of a cylindrical core tool having a corrugated profile on the outer side and/or additional circumferential auxiliary threads wound in a helix manner and comprising fixing threads running transversely or diagonally to the threads or fibres or cord filaments running in the longitudinal direction and holding these in position in a vulcanizable material or in an elastomer or in a thermoplastic;   b) forming a roll from the surface structure produced in step a);   c) winding a section separated from the rolled-up surface structure onto a cylindrical or hollow cylindrical core tool having a corrugated profile on the outer side;   d) action of a press bandage, pressing film, or external pressure (autoclave) or of the upper/outer tool and of the lower/inner tool of a shape-molding tool having an upper/outer mold corresponding to the shape of the molded body to be produced having the corrugated profile, wherein the molds of the upper/outer mould and of the lower/inner mold complement each other to form the corrugated shape of the molded body, on the section of the surface structure arranged on the cylindrical core tool to form the bellows;   optionally   d1. Action of a press bandage, pressing film, excess pressure (autoclave), downward-movable pressing rollers or round profiles which are put in place before bringing up the press bandage, pressing film etc. in order to improve the shaping; and/or   d2. expansion by internal pressing of the preform/blank by means of balloon (bladder) or by direct blowing in of air or steam instead of the core tool to the inner contour of the closed upper/lower tool;   e) removing the cylindrical core tool to release the bellows;   f) optionally inserting ring members made of a metal material into the troughs formed in the bellows.   
     
     
         3 . Method for producing a flexible tubular molded body, having a wall surface without or with a corrugated profile such as bellows, molded hose, molded arcs for air intake, turbo charging, cooling water and oil circuits and air conditioning, for use in vehicle construction, ship building, mechanical engineering and aircraft construction, having at least one strength support insert which is embedded in a vulcanizable material, in an elastomer or in a thermoplastic, using an extrusion system comprising an extruder, a feed device for the threads or for the cord filaments, a device for fixing the threads or the cord filaments, possibly a device for applying flyer threads, a second extruder and a device for cutting to length individual sections of a strand-shaped endless blank to form individual blank sections according to  claim 1 , comprising the following steps:
 a) producing a strand-shaped tubular molded body having a circumferential wall without or with a corrugated profile by means of an extrusion system for elastomers or thermoplastic by shaping a strand-shaped tubular blank by means of a first extruder;   b) feeding threads or cord filaments running in the longitudinal direction of the blank for depositing on the surface of the blank;   b1) feeding the longitudinal-lying threads, fibres or cord filaments, their position possibly fixed with light transverse threads, as flat material by front-side pulling into a double-T co-extruder, where the flat-lying strength support is formed round inside the co-extruder above the first extrusion on the outer surface of this inner core and is then oversprayed with a cover layer by the second extruder mouth;   c) fixing the threads or cord filaments deposited on the strand-shaped blank by means of supplied fixing threads or helix flyers;   d) applying another layer of an elastomer or by means of a second extruder on the strand-shaped blank produced in step c);   e) arbitrarily repeating steps a), b), b1), c) and d) to produce several layers with strength supports;   e1) cutting to length individual blank sections from the blank produced in step d);   f) deforming the individual blank sections obtained in step e) to form a bellows or arc using a molding tool which produces the corrugated profile or arc having an upper/outer mold having a shape corresponding to the shape of the molded body to be produced the corrugated profile and having a lower mold having lower/inner mold corresponding to the shape of the molded body to be produced with the corrugated profile, wherein the forms of the upper mould and the lower mold complement each other to form the corrugated shape of the molded body;   f1) Action of a press bandage, pressing film, excess pressure (autoclave), downward-movable pressing rollers or round profiles which are put in place before bringing up the press bandage, pressing film etc in order to improve the shaping; and/or   f2) expansion by internal pressing of the preform/blank by means of balloon (bladder) or by direct blowing in of air or steam instead of the core tool to the inner contour of the closed upper/lower tool.   
     
     
         4 . Method for producing a flexible tubular molded body, having a wall surface without or with a corrugated profile such as bellows, molded hose, molded arcs for air intake, turbo charging, cooling water and oil circuits and air conditioning, for use in vehicle construction, ship building, mechanical engineering and aircraft construction, having at least one strength support insert which is embedded in a vulcanizable material, in an elastomer or in a thermoplastic, using an extrusion system comprising a T-co-extruder, with front-side feed for the threads or for the cord filaments as web-shaped flat material, which is shaped round above the first extrusion core in the extruder head over this first core and then over molded by the second extruder nozzle, where this system can stand alone, either then followed by a cutting to length device or for producing further layers of strength supports followed by a feed device for the threads or the cord filaments followed by a device for fixing the threads or the cord filaments, possibly a device for applying flyer threads, a second extruder and a device for cutting to length individual sections of a strand-shaped endless blank to form individual blank sections according to  claim 1 , comprising the following steps:
 a) producing a strand-shaped tubular molded body having a circumferential wall without or with a corrugated profile by means of a T-co-extrusion system by shaping a tubular inner core by means of a first extruder ring nozzle by means of which, by means of front-side pulling of strength support as web-shaped flat material, with/without fixing threads, this strength support, shaped round inside the extruder head, is deposited on the pre-extruded inner core and already oversprayed with a second layer or elastomer or thermoplastic by the second extruder ring nozzle inside the extruder head and thus forms a strand-shaped tubular blank; 
 b) feeding threads or cord filaments running in the longitudinal direction of the strand-shaped blank for depositing on the surface of the blank; 
 c) fixing the threads or cord filaments deposited on the strand-shaped blank by means of supplied fixing threads; 
 d) applying a layer or several further layers of an elastomer or thermoplastic by means of a second or further extruders on the strand-shaped blank produced in step c); 
 e) cutting to length individual blank sections from the blank produced in step d); 
 f) deforming the individual blank sections obtained in step e) to form a bellows using a molding tool which produces the corrugated profile having an upper mold having a shape corresponding to the shape of the molded body to be produced with a shape corresponding to the corrugated profile and having a lower mold having a mold corresponding to the shape of the molded body to be produced with the corrugated profile, wherein the forms of the upper mold and the lower mold complement each other to form the corrugated shape of the molded body 
 f1) Action of a press bandage, pressing film, excess pressure (autoclave), downward-movable pressing rollers or round profiles which are put in place before bringing up the press bandage, pressing film etc in order to improve the shaping; and/or 
 f2) expansion by internal pressing of the preform/blank by means of balloon (bladder) or by direct blowing in of air or steam instead of the core tool to the inner contour of the closed upper/lower tool.