Press brake with crown adjustment and movable table adjustment calculate from first and second die contiguous position

• US 5,272,643 A
• Filed: 04/29/1991
• Issued: 12/21/1993
• Est. Priority Date: 08/31/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Original Assignee: Kabushiki Kaisha Komatsu Seisakusho
• Inventors: Tokai, Shigeru
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): GORDON, PAUL P
• Application Number:
  US07/674,349
• Time in Patent Office: 967 Days
• Field of Search: 364/474.07, 364/476, 72/389, 72/380, 72/448
• US Class Current: 700/165
• CPC Class Codes: B21D 5/02 on press brakes without making use of clamping means
• CPC Class Codes: B21D 5/0272 Deflection compensating means
• CPC Class Codes: B30B 15/007 Means for maintaining the press table, the press platen or the press ram against tilting or deflection
• CPC Class Codes: B30B 15/26 Programme control arrangements

Abstract

An apparatus for controlling a press brake is advantageously employable for a press brake for which a high operational efficiency and a high working accuracy are required. In response to inputting of working conditions inclusive of a target bending angle for a plate, the apparatus calculates displacement of a load active on a stationary table and a movable table, automatically calculates a quantity of crowning to be adjusted based on results derived from the foregoing calculation and then calculates the present position assumed by the movable in additional consideration of the quantity of crowning to be adjusted, based on results derived from the aforementioned calculations. The press brake accurately bends the plate based on the thus derived quantity of crowing to be adjusted and the present position assumed by the movable table without an occurrence of malfunction of so-called intermediate opening of the bent plate.

Claims

1. Apparatus for controlling a press brake (1) for bending a plate (4) to a target bend angle (WA) by pressing the plate between a first die (2) fixedly mounted to a first beam (3) and a second die (5) fixedly mounted to a second beam (7), one of the beams (3, 7) being movable towards the other to press the plate, and one of the beams being adjustable to vary the amount of crowning of that adjustable beam (3 or 7), the apparatus comprising:

crowning adjustment means (9) for adjusting the amount of crowning of the adjustable beam;

calculating means (10) for calculating the position to which the movable beam (3 or

     7) should be moved to bend the plate to the target bend angle;

position adjustment means for adjusting the position to which the movable beam should be moved; and

drive means (6R, 6L) for driving the movable beam to move to the calculated position;

calculating means for;

calculating displacements (EUT, EL, DC) of the first beam (3) and the second beam (7) under load when the plate is pressed between the dies, and deflections (DU, DL) of the beams (3,

     7) when the first die and the second die approach closest to each other, based on a plurality of working conditions for bending the plate including the target bend angle; and

calculating an amount of crowning (CW), based on the calculated die placements and deflections;

the amount of crowning of the adjustable beam being adjusted by the crowning adjustment means (9) to the calculated amount of crowning;

the calculation of the position to which the movable beam should be moved is based on the calculated displacements, deflections and amount of crowning; and

the adjustment of the position to which the movable beam is moved by said adjustment position means is based on the calculated displacements, deflections and amount of crowning.

2. Apparatus as claimed in claim 1, including inputting means for allowing the plurality of working conditions for bending the plate to be input into the apparatus.