EP0418114A2

EP0418114A2 - Apparatus and method for bending of thin sheet metals

Info

Publication number: EP0418114A2
Application number: EP90402411A
Authority: EP
Inventors: Veikko Pitkänen
Original assignee: TOOLSYSTEM Oy
Current assignee: TOOLSYSTEM Oy
Priority date: 1989-09-11
Filing date: 1990-08-31
Publication date: 1991-03-20
Also published as: FI894259A0; FI85112C; FI85112B; EP0418114A3; FI894259A

Abstract

This invention concerns bending apparatus for thin sheet materials, which apparatus comprises a frame (11) and at least two facingly arranged bending units (1, 2), which are attached to the frame, equipped with bending members connected to drive means and complemented with a top and bottom push clamp (4, 5). At least one bending unit (2) is arranged transferrable in respect to a second bending unit (1), placed essentially perpendicular to the first unit, in order to align the sheet (10) to be bent to a desired bending position. Thereby the top and bottom push clamps (4, 5) act as sheet clamps serving to transfer the sheet during alignment and/or to determine the bending position of the sheet. Said transferrable bending unit (2) is mounted on guides (12) and the positioning of the unit is arranged controllable by digital means.

Description

The present invention relates to a bending apparatus for thin sheet metals, said apparatus comprising a frame and at least two facingly arranged bending units, which are attached to the frame, equipped with bending members connected to drive means and complemented with a top and bottom push clamp. Furthermore, the inventions concerns a method in accordance with the preamble of claim 6 for bending thin metal sheets.
The aim of the invention is to achieve a bending apparatus of thin sheet metals which is applicable to the bending of different widths of thin sheet or band metals. To attain this goal, the bending apparatus in accordance with the invention is characterized by having at least one bending unit arranged transferrable in respect to a second bending unit, placed essentially perpendicular to the first unit, in order to align the sheet to be bent to a desired bending position, where the top and bottom push clamps act as sheet clamps serving to transfer the sheet during alignment and/or to determine the bending position of the sheet. Furthermore, the invention aims to achieve a method for bending thin sheet or band metals of different widths, for which goal the method in accordance with the invention is characterized by the preamble of claim 6.
In the following the invention is described with reference to the enclosed drawings in which

Figure 1 shows the bending apparatus in accordance with the invention in an end view,
Figure 2 shows diagrammatically the bending elements of a bending unit, and
Figure 3 shows diagrammatically the phases of bending a piece of thin sheet metal.

According to Figs. 1 and 3 the apparatus comprises a frame 11 and at least two facingly placed bending units 1, 2, which are attached to the frame 11. The bending units are provided with bending members complemented with drive means and with a top and bottom push clamp 4 and 5, respectively. The bending members include, i.a., a bending cylinder (not shown) and bend wings 3a and 3b, which are articulated by at least one linking rod 13, as well as members for controlling the sheet alignment in horizontal and vertical directions such as, for instance, a rear gage 8 and a shaft 9 serving these functions, respectively. In the illustrated exemplifying embodiment the top push clamps 4 are arranged transferrable by means of, for instance, push cylinders, while the bottom push clamps 5 are arranged stationary. In the bending apparatus according to Fig. 1, the bending unit 2 is arranged movable on guides 12 in a direction essentially perpendicular to the bending unit 1. The positioning of the transferrable bending unit 2 is advantageously arranged controllable by digital means. The positioning of the sheet to be bent (designated by reference number 10 in Fig. 3) is arranged in the exemplifying embodiment by adapting the bend wings 3a to act as positioning means, against which the sheet to be bent is first aligned to determine the exact position of the sheet. The position of the bend wing 3a in turn can be determined with the help of, for instance, positions of the rear gage 8 and the shaft 9.
The method according to the invention is implemented with the help of the apparatus in accordance with the exempli fying embodiment for instance 50 that the sheet is first brought to the gap between the bending units 1, 2 and positioned between the top and bottom push clamps 4, 5 of the stationary bending unit 1 against the bend wing 3a. Next, the transferrable bending unit 2 is placed with the help of the bend wing 3a against the other edge of the sheet. Next, after the sheet position is determined in the above manner, the sheet is positioned to the desired bending position by using the top and bottom push clamps 4, 5 as sheet clamps. This phase of positioning can be implemented by, for instance, in the first stage the push clamps 4, 5 of the bending unit 1 are holding the sheet to be bent while the push clamps 4, 5 the transferrable bending unit 2 are withdrawn, thus permitting the transfer of the transferrable bending unit 2 to a desired position of bending, after which the push clamps are closed and the sheet is bent to the desired direction. Subsequently, the push clamps of the stationary bending unit can be withdrawn and the sheet can be moved by the transferrable bending unit 2 to a desired position of bending in the stationary bending unit 1, after which the push clamps of the stationary bending unit are closed against the sheet and its other edge is bent to the desired direction. This procedure can be continued alternately until each edge of the sheet is bent to the desired shape such as, for instance, a U-, C- or pan shape. The finished item is finally returned to the center position for removal from the apparatus.
In the exemplifying embodiment illustrated in Fig. 3, the bent sheet 10 is initially positioned by means of the bend wings 3a to the desired position of bending, after which the downward bending of both edges of the sheet 10 is made by the bend wings 3a (phase 1). Next, the top push clamp 4 of the stationary bending unit 1 is withdrawn and the sheet 10 is transferred with the help of the transferrable bending unit 2 toward the stationary bending up to the next position of bending (phase 2). The top push clamp 4 of the stationary bending unit is then pushed down and the edge of the sheet son the side of the stationary bending unit 1 is bent upward at the newly set position by the lower bend wing 3b, after which the push clamp 4 of the transferrable bending unit is withdrawn and said bending unit 2 is transferred toward the stationary bending unit 1 up to the next position of bending (phase 3). Subsequently, the top push clamp 4 of the transferrable bending unit 2 is pushed down and the edge of the sheet on the side of the transferrable bending unit 2 is bent upward by the lower bend wing 3b (phase 4). Finally the top push clamps 4 of both bending units 1, 2 are withdrawn and the finished item is removed from the apparatus.
The above-described examples are portrayed only to illustrate a few preferred embodiments of the invention, without thereby in any manner restricting the scope of application disclosed in the appended claims.

Claims

1. A bending apparatus for thin sheet metals, said apparatus comprising a frame (11) and at least two facingly arranged bending units (1, 2), which are attached to the frame, equipped with bending members connected to drive means and complemented with a top and bottom push clamp (4, 5) characterized in that at least one bending unit (2) is arranged transferrable in respect to a second bending unit (1), placed essentially perpendicular to the first unit, in order to align the sheet (10) to be bent to a desired bending position, where the top and bottom push clamps (4, 5) act as sheet clamps serving to transfer the sheet during alignment and/or to determine the bending position of the sheet.

2. An apparatus in accordance with claim 1, characterized in that said transferrable bending unit (2) is arranged movable on guides (12) and that the positioning of the bending unit 2 is advantageously arranged controllable by digital means.

3. An apparatus in accordance with claim 1 or 2, characterized in that bending in both bending units (1, 2) can be performed upward and/or downward.

4. An apparatus in accordance with any of the foregoing claims 1...3, characterized in that both bending units (1, 2) are orthogonally transferrable to each other.

5. An apparatus in accordance with any of the foregoing claims, characterized in that bend wings (3) in the bending units act as clamping means, or alter natively, the bending units are complemented with separate clamping means, which means are used for the positioning of the sheet in respect to the bending units (1, 2) prior to the positioning of the sheet to the bending line position.

6. An apparatus in accordance with any of the foregoing claims 1...5, characterized in that the bending members of the bending unit (1, 2) include two bend wings (3a, 3b) which are connected by at least one linking rod (13), whereby the movement of the bend wings can be implemented by means of an single actuator.

7. A method for bending thin sheets into, for instance, U-, C- or pan shapes, using an apparatus comprising a frame (11) and at least two facingly arranged bending units (1, 2), which are attached to the frame, equipped with bending members connected to drive means and complemented with a top and bottom push clamp (4, 5), characterized in that at least one bending unit (2) in the apparatus is arranged transferrable essentially perpendicularly in respect to a second bending unit (1), said method including at least the following work phases:

(A) transfer of the sheet into a gap between the bending units (1, 2) of the bending apparatus;

(B) positioning of the sheet by means of the bend wings (3) or separate positioning means attached to the bend wings;

(C) positioning of the sheet by means of the transferrable bending unit (2) to the desired position of bending, wherein the top and bottom push clamps (4, 5) are used as sheet clamps during the lateral transfer of the sheet; and

(D) bending of the sheet in the desired direction.

8. A method in accordance with claim 7, characterized in that the phases (C) and (D) are repeated until the desired shape of the sheet is attained.