Metal deforming – With indication of condition or position of work – product,... – Including deformation by simple bending
Patent
1996-08-19
1998-01-06
Larson, Lowell A.
Metal deforming
With indication of condition or position of work, product,...
Including deformation by simple bending
723893, 72 162, B21C 5100
Patent
active
057042381
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an automatic die driving amount correction method well adopted for use in a bending machine such as a press brake to measure the bending angle of a workpiece during bending operation and correct the driving amount of a die according to the measured value of the bending angle.
BACKGROUND ART
In a known method for bending a sheet-like workpiece by use of a bending machine such as a press brake, various kinds of information including workpiece conditions (e.g., the thickness and material of a workpiece), die conditions and machine conditions are input in an NC device; a driving amount for a movable die (i.e., either the upper die or lower die) is calculated from the input information; and the movable die is driven to the drive end thus calculated to produce a desired bent article.
Even though driving of the movable die is based on many pieces of information, the above method often fails in obtaining a desired bending angle and therefore cannot avoid an error in a bending angle, because of variations from batch to batch in workpiece thickness, characteristics and processing conditions.
There have been made one attempt to achieve high-accuracy bending operation free from bending angle errors due to variations in materials etc., in which the bending angle of a workpiece is measured during bending operation and according to the measured value, the driving amount of the die is corrected. Japanese Patent Laid-Open Publication No. 5-69046 (1993) discloses one example of bending machines incorporating a bending angle measuring means for performing such correction. According to the metal plate bending machine disclosed in this publication, a slit light is projected onto the external surface of a metal sheet being bent to form a linear projected light image which is then picked up by a photographing means and based on this picked-up image, the bending angle of the metal sheet is calculated to correct the driving amount of the die.
Bending machines having such a conventional bending angle measuring means, however, present the disadvantage that they have difficulty or sometimes fail in measuring bends formed in workpieces of some configurations. In such a case, there inevitably occurs an error in the angle of the bend. Another disadvantage of the conventional bending machines of this type is such that when bending a workpiece at a plurality of positions to form a plurality of bends, driving of the die must be interrupted to make an angle measurement whenever bending of a bend is performed. This results in prolonged processing time.
DISCLOSURE OF THE INVENTION
The invention has been made for the purpose of overcoming these problems and therefore one of the objects of the invention is to provide an automatic die driving amount correction method with which improved bending angle accuracy can be ensured for articles having a plurality of bends some of which are difficult or impossible to measure and with which processing time can be considerably reduced.
The above object can be accomplished by an automatic correction method for correcting the driving amount of a movable die based on a measured value obtained by measuring the bending angle of a workpiece during bending operation, characterized in that:
for bending the workpiece at a plurality of positions to form a plurality of bends, a correction value for the driving amount of the die to form a certain bend, the correction value being based on a measured value obtained from a measurement of the angle of the certain bend, is utilized for calculation of a correction value for the driving amount of the die to form any one of the remaining bends.
According to the invention, for bending a workpiece at a plurality of positions to form a plurality of bends, the angle of a certain bend is first measured during bending operation and a correction value for the driving amount of the die is calculated from the measured value. With this correction value, bending is then performed to form the certain bend. When bending is performed
REFERENCES:
patent: 4772801 (1988-09-01), Fornerod et al.
patent: 4947666 (1990-08-01), Hametner et al.
patent: 5055752 (1991-10-01), Leistensnider et al.
patent: 5148693 (1992-09-01), Sartorio et al.
patent: 5285668 (1994-02-01), Tokai
patent: 5375340 (1994-12-01), Gerritson
patent: 5461893 (1995-10-01), Tyler
patent: 5497647 (1996-03-01), Nagakura
Komatsu Ltd.
Larson Lowell A.
Tolan Ed
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