Pressing tool and pressing process

Abstract

A pressing tool for tightly pressing sleeve-like fittings ( 32 a ) includes a hydraulic cylinder device having a fork-like connecting part ( 7 ) and a drive motor. A pressing jaw ( 51 ) with a fastening pin ( 50 ) is fastened in the fork-like connecting part ( 7 ). A piston of the hydraulic cylinder device, which piston is connected to a piston rod ( 6 ), is moved out of the starting position in the cylinder by the drive motor. As a result, the piston rod ( 6 ) is extended from the cylinder. As a result of the movement of the piston rod ( 6 ), the cheek plates ( 51 a , 51 b ) of the pressing jaw ( 51 ) are moved apart in the region of actuation surfaces ( 8 a , 8 b ) of the cheek plates ( 51 a , 51 b ) in order to press the cheek plates ( 51 a , 51 b ) together in the region of the fittings ( 32 a ) to be pressed. In order to carry out a pressing process ( 44 ) safely, the pressing tool has, in the region of the fork-like connecting part ( 7 ), a presence sensor ( 52 ) which checks for the presence of the pressing jaw ( 51 ) and, in the case of an absent or incorrectly fastened pressing jaw ( 51 ), triggers a warning signal ( 45 a ) and, after a delay, switches off the pressing tool if a properly inserted pressing jaw ( 51 ) is still not present.

1 . Pressing tool for tightly pressing sleeve-like fittings ( 32   a ) onto two pipe ends for the purpose of connecting the two pipes, comprising a hydraulic cylinder device with a fork-like connecting part ( 7 ), a pressing jaw ( 51 ) which can be interchangeably fastened in this connecting part ( 7 ) by means of a fastening pin ( 50 ), and a drive motor for actuating a piston rod ( 6 ) as an actuating member for moving at least one cheek plate ( 51   a ,  51   b ), characterized in that a presence sensor ( 52 ) for the pressing jaw ( 51 ) is provided, which delivers a signal by means of which, in the event of an absent or incorrectly inserted pressing jaw ( 51 ), the initiation of a pressing process ( 44 ) can be prevented or an initiated pressing process ( 44 ) can be terminated.  
     
     
         2 . Pressing tool according to    claim 1   , characterized in that the presence sensor ( 52 ) is one which measures without contact, preferably one which measures inductively, and makes it possible to detect the presence of the pressing jaw ( 51 ).  
     
     
         3 . Process using a pressing tool according to    claim 1   , the clamping movement of at least one cheek plate ( 51   a ,  51   b ) being permitted via the piston rod ( 6 ) and a transmission device, characterized in that, after an initialization step ( 42 ), in which the self-test, start test and/or service test are carried out, a pressing jaw presence check ( 45 ) is carried out in a repeatable second step, before a pressing process ( 44 ) is made triggerable, and, with an absent or incorrectly inserted pressing jaw ( 51 ), a warning signal ( 45   a ) is output and—optionally after a repetition of the pressing jaw presence check ( 45 )—the pressing process is not initiated or the initiated pressing process ( 44 ) is switched off after a delay if the pressing jaw ( 51 ) still has not been correctly inserted at this time.  
     
     
         4 . Pressing process for tightly pressing sleeve-like fittings ( 32   a ), using a pressing tool according to    claim 1   , the piston rod ( 6 ) actuating the clamping movement of at least one cheek plate ( 51   a ,  51   b ) via a transmission device, characterized in that, after an initialization step ( 42 ), in which the self-test, start test and service test are carried out, a pressing jaw presence check ( 45 ) is carried out in a repeatable second step, before a pressing process ( 44 ) is made triggerable, and, in the case of a correctly inserted pressing jaw ( 51 ), an allocation check ( 46 ) is carried out after a short delay in order to assign a piston position range value to the inserted pressing jaw ( 51 ), and a locking check ( 47 ) is carried out as a further checking step before enabling the triggerability of a pressing process ( 44 ), in order to trigger at least a warning signal ( 47   a ) if a fastening pin ( 50 ) has not been secured, and then to initiate the pressing process ( 44 ).  
     
     
         5 . Process according to    claim 3   , characterized in that the pressing jaw presence check ( 45 ) detects an inserted pressing jaw ( 51 ) in a non-contact, in particular inductive, measuring step and that the locking check ( 47 ) preferably with a magnetic field measurement by means of a Hall sensor—detects the fastening pin ( 50 ) in its secured position.  
     
     
         6 . Process according to    claim 3   , characterized in that, if the fastening pin ( 50 ) is not secured, the continuation of the pressing process ( 44 ) is postponed for a certain time, optionally after a repetition of the locking check step ( 47 ), if the fastening pin ( 50 ) still has not been properly locked at this time.