Apparatus and method for making a z-shaped profile on a sheet metal part

Abstract

An apparatus for making a Z-shaped profile on a sheet metal part having a first mould element acting as punch, a second mould element acting as die and a third mould element acting as sheet pressing element is provided. The second and third moulds element have respective flat clamping surfaces extending parallel to each other and are movable between an open position which allows insertion of the sheet metal part, and a closed position, in which the clamping surfaces are in contact with opposite sides of the sheet metal part. The first mould element is movable by translation along a working direction inclined to a direction perpendicular to the clamping surfaces towards a final working position in which the first mould element presses the sheet metal part against the second mould element.

1 . An apparatus for making a Z-shaped profile on a sheet metal part, the apparatus comprising a first mould element acting as punch, a second mould element acting as die, and a third mould element acting as sheet pressing element,
 wherein the second mould element and the third mould element have respective flat clamping surfaces extending parallel to each other, and are movable relative to each other between an open position, in which said clamping surfaces are spaced apart from each other to allow insertion of the sheet metal part to be worked, and a closed position, in which said clamping surfaces are in contact with opposite sides of the sheet metal part to clamp said part,   wherein the first mould element is mounted so as to be movable by translation along a working direction inclined to a direction perpendicular to said clamping surfaces, once the second mould element and the third mould element are in the above-mentioned closed position with the sheet metal part clamped between the respective clamping surfaces, towards a final working position in which the first mould element presses the sheet metal part against the second mould element,   wherein the first mould element and the second mould element have respective working surfaces shaped in such a way as to define, when said first and second mould elements are in the final working position, the geometry of a first 90-degree bend and the geometry of a second 90-degree bend of the Z-shaped profile to be made,   wherein the apparatus further comprises a control system means arranged to control the movements of the first mould element along said working direction, of the second mould element in a horizontal direction and of the third mould element along the working direction, and   wherein said control system comprises a first carriage, which is mounted so as to be movable by translation along said working direction and carries the first mould element and the third mould element, a second carriage, which is mounted so as to be movable by translation in a horizontal direction and carries the second mould element, and a wedge-shaped control member, which is mounted so as to be movable by translation in a vertical direction and forms a first flat control surface, configured to cooperate with a corresponding control surface of the first carriage, and a second flat control surface, configured to cooperate with a respective control surface of the second carriage, in such a manner that the vertical movement of the control member first causes the second mould element to move in a horizontal direction towards the sheet metal part, then the third mould element to move along said working direction towards the sheet metal part and finally the first mould element to move along said working direction towards the sheet metal part until reaching said final working position.   
     
     
         2 . The apparatus of  claim 1 , wherein the third mould element is also mounted so as to be movable by translation along said working direction, in such a manner that the displacement of the respective clamping surface to and from the clamping surface of the second mould element occurs by translation along said working direction. 
     
     
         3 . The apparatus of  claim 2 , wherein the first mould element and the third mould element have respective flat guide surfaces which extend along said working direction and are held in contact with each other. 
     
     
         4 . The apparatus of  claim 3 , wherein the first mould element has a first flat working surface extending parallel to the clamping surfaces of the second mould element and of the third mould element, and a second flat working surface extending perpendicular to the first working surface of the first mould clement, joining the latter with the guide surface of the first mould element, and wherein the second mould element has a first flat working surface extending parallel to the clamping surfaces of the second mould element and of the third mould element, and a second flat working surface extending perpendicular to the first working surface of the second mould element, joining the latter with the clamping surface of the second mould element, in such a manner that, when the first mould element is in the final working position, the clamping surface of the third mould element forms with the second working surface of the first mould element the an extrados of the first 90-degree bend of the Z-shaped profile, the second working surface of the first mould element forms with the first working surface of the first mould element the an intrados of the second 90-degree bend of the Z-shaped profile, the clamping surface of the second mould element forms with the second working surface of the second mould element the an intrados of the first 90-degree bend of the Z-shaped profile, and the second working surface of the second mould element forms with the first working surface of the second mould element the an extrados of the second 90-degree bend of the Z-shaped profile. 
     
     
       5. The apparatus of  claim 1 , wherein said control system further comprises a hydraulic drive configured to control the translational movement of the control member in a vertical direction. 
     
     
         6 . The apparatus of  claim 1 , wherein the first mould element is configured to make an additional bend on the sheet metal part, in addition to the Z-shaped profile. 
     
     
         7 . The apparatus of  claim 1 , further comprising four groups of main mould elements, each configured to make a Z-shaped profile on a respective side of a perimeter edge of the sheet metal part, and four groups of corner mould elements, each configured to make a Z-shaped profile on a respective corner portion connecting two adjacent sides of the perimeter edge of the sheet metal part, wherein each of said groups of main mould elements and said groups of corner mould elements comprises said first mould element, said second mould element and said third mould element, whereby the apparatus is capable of making a Z-shaped profile on the entire perimeter edge of the sheet metal part. 
     
     
         8 . A method for making a Z-shaped profile on a sheet metal part by means of an apparatus according to  claim 1 , the method comprising:
 (a) clamping the sheet metal part between the clamping surfaces of the second mould element and of the third mould element, and   (b) urging the first mould element against the sheet metal part along said working direction until said final working position is reached, in which the first mould element presses the sheet metal part against the second mould element.