Tie bar withdrawing device

Abstract

A post-extracting device for at least one post ( 7 a, 7 b, 7 c, 7 d ) of a molding machine ( 1 ) having a fixed clamping plate ( 2 ) with a first casting-mold half ( 3 ) arranged thereon and a movable clamping plate ( 4 ) with a second casting-mold half ( 5 ) arranged thereon. The movable clamping plate can be moved on posts detachably fastened in the fixed clamping plate. The post-extracting device is characterized in that the post-extracting device has the following units: a fastening device ( 10 a, 10 b, 10 c, 10 d ) arranged on the movable clamping plate, for detachably connecting to a post and a further fastening device ( 15 a, 15 b ) for detachably connecting to a post, which is arranged on a bar ( 11 a, 11 b ), which is located on the side of the movable clamping plate facing away from the fixed clamping plate. A molding machine and method for extracting a post from such a molding machine are also disclosed.

1 . Tie bar withdrawing device for at least one tie bar of a casting machine, having a fixed die plate with a first casting-mould half arranged thereon and having a movable die plate with a second casting-mould half arranged thereon,
 wherein the movable die plate can be moved on tie bars that are fastened releasably in the fixed die plate wherein the tie bar withdrawing device has the following units:   a fastening device arranged on the movable die plate for releasable connection to a tie bar,   a further fastening device for releasable connection to a tie bar, said further fastening device being arranged on a rack which is located on that side of the movable die plate that is remote from the fixed die plate.   
     
     
         2 . Tie bar withdrawing device according to  claim 1 , wherein the fastening device, for releasable connection to a tie bar, of the tie bar withdrawing device, said fastening device being arranged on the movable die plate, is a coupling by way of which optionally a form-fitting or force-fitting connection to the tie bar can be established. 
     
     
         3 . Tie bar withdrawing device according to  claim 1 , wherein the further fastening device for releasable connection to a tie bar, said further fastening device being arranged on the rack, comprises a clamping cylinder that acts on the tie bar from above and a supporting cylinder that acts on the tie bar from below. 
     
     
         4 . Casting machine having a fixed die plate with a first casting-mould half arranged thereon and having a movable die plate with a second casting-mould half arranged thereon, wherein the movable die plate can be moved on tie bars that are fastened releasably in the fixed die plate, wherein the casting machine comprises a tie bar withdrawing device according to one of  claims 1  to  3 . 
     
     
         5 . Casting machine according to  claim 4 , wherein for two tie bars of the casting machine in each case one tie bar withdrawing device is provided. 
     
     
         6 . Casting machine according to  claim 4 , wherein, the rack or the racks of the tie bar withdrawing device is/are arranged on a crossbar which is fastened to the ends of the lower tie bars of the casting machine. 
     
     
         7 . Casting machine according to  claim 6 , wherein the crossbar is fastened to one end of a closing cylinder, the other end of which is connected to the rear side of the movable die plate. 
     
     
         8 . Casting machine according to  claim 6 , wherein the crossbar is supported on the ground by at least one supporting element. 
     
     
         9 . Method for withdrawing at least one tie bar from a casting machine, wherein the casting machine comprises a fixed die plate with a first casting-mould half arranged thereon and a movable die plate with a second casting-mould half arranged thereon, and the movable die plate is guided on tie bars that are fastened releasably in the fixed die plate, comprising the steps of:
 a) releasing the releasable fastener of the tie bar in the fixed die plate in a machine position in which the movable die plate is in the closing position.   b) fixing the tie bar to the movable die plate by closing the fastening device arranged on the movable die plate,   c) moving the movable die plate in the opening direction to a position in which the tie bar has been introduced into a further fastening device for releasable connection to a tie bar, said further fastening device being arranged on a rack which is located on that side of the movable die plate that is remote from the fixed die plate,   d) fixing the tie bar to the rack by closing the fastening device arranged on the rack,   e) opening the fastening device arranged on the movable die plate,   f) moving the movable die plate in the closing direction,   g) optionally repeating steps b) to e) until the tie bar has been withdrawn to a predetermined degree from the region between the fixed and movable die plates.   
     
     
         10 . Method according to  claim 9 , wherein steps b) to e) are repeated at least once in step g). 
     
     
         11 . Method according to  claim 9 , wherein the two upper tie bars of a casting machine are withdrawn simultaneously or individually. 
     
     
         12 . Method according to  claim 9 , wherein in step d), the tie bar is fixed to the rack by way of a clamping cylinder that acts on the tie bar from above and a supporting cylinder that acts on the tie bar from below. 
     
     
         13 . Method according to  claim 9 , wherein, in step c), the movable die plate is moved into the opening position. 
     
     
         14 . Method according to  claim 9 , wherein, in step f), the movable die plate is moved into the closing position.