Multi-shaft bending machine for bending rectangular duct body

Abstract

A multi-shaft bending machine for bending two rectangular duct bodies, such as trunk lead hanger arms for a vehicle at the same time. Barrier pieces are installed in a mandrel including three rollers and a rectangular duct body support that forms a bending machine so that two rectangular duct bodies are not mutually influenced when a bending work is performed on the two rectangular duct bodies. A rotation plate is rotated by a plurality of shafts connected to a driving motor through clutch gears. Accordingly, a difference between strain rates on the outer and inner sides of a bending part can be reduced, lubricating oil injected into the oil grooves of the rollers performs a lubrication action, and the structure of a bending machine can become simple because the rotation plate is rotated by the plurality of shafts connected to the driving motor through the clutch gears.

What is claimed is: 
     
         1 . A multi-shaft bending machine for bending a rectangular duct body, the multi-shaft bending machine comprising a rotation plate ( 32 ) in which a model body ( 33 ) having a shape identical with a shape of an outward appearance of a rectangular duct body to be bent and a clamp ( 34 ) for fixing a front end of the rectangular duct body ( 40 ) are formed, a rectangular duct body support ( 43 ), a bending driving unit ( 30 ), and a mandrel driving unit ( 20 ), wherein:
 a shaft  1  ( 31 ), a shaft  2  ( 31 ′), and a shaft  3  ( 31 ″) in which respective driving gears ( 37 ) are formed are configured in the rotation plate ( 32 ), the shaft  1 , the shaft  2 , and the shaft  3  are connected to a prime gear ( 38 ) of a driving motor M through respective clutch gears ( 39 ), and a control unit ( 30 ′) for controlling the clutch operations of the driving motor M and the clutch gears ( 39 ) is connected to one side of the driving motor M;   a screw hole ( 7 ) for a connection with an actuation rod ( 26 ) is formed at a rear end of a main body ( 2 ) in a mandrel ( 1 ) connected to a cylinder ( 25 ) and an actuation rod ( 26 ) that form a mandrel driving unit ( 20 ), a round part ( 3 ) for preventing interference with the bending of the rectangular duct body ( 40 ) is formed at a front end of the mandrel ( 1 ), and a shaft insertion hole ( 4 ) is formed to penetrate a side of the mandrel ( 1 ); and   coupling pieces ( 5 ) are connected to a coupling shaft  6  on both sides of a shaft insertion hole ( 4 ), and a roller coupling shaft ( 12 ) is connected between the coupling pieces ( 5 ) so that three rollers ( 8 ) are individually rotated; and   each of the rollers ( 8 ) comprises a protruded part ( 10 ) having an oil groove ( 10 ′) formed at a center of the protruded part ( 10 ), depressed parts ( 9 ) formed on both sides of the protruded part ( 10 ), and circular oil grooves ( 11 ) filled with lubricating oil and formed on both sides of the depressed parts ( 9 ).   
     
     
         2 . The multi-shaft bending machine of  claim 1 , wherein main body depressed parts ( 13 ) and main body protruded parts ( 14 ) for preventing depression parts ( 41 ) of the rectangular duct body from being damaged due to the depressed parts ( 9 ) and the protruded parts ( 10 ) of the rollers ( 8 ) are formed in the round part ( 3 ) formed at an end of one side of the main body ( 2 ) of the mandrel ( 1 ). 
     
     
         3 . The multi-shaft bending machine of  claim 1 , wherein barrier pieces ( 43 ′ and  21 ′) are formed in the rectangular duct body support ( 43 ) and a support roller ( 21 ), respectively, so that two rectangular duct bodies are separated and are not mutually influenced each other.