Method and apparatus for automatically compensated tube bending

Claim 2

In a method of bending a tube having substantially deformable and partially resilient material characteristics to a shape specified by given bend data consisting of, at least one bend angle with a given degree of bend (DOB) and a bend radius (RB), and straight distances between bends (DBB) with a tube bending machine having a bend die with a given bend die radius (RC), said given degree of bend (DOB), bend radius (RB), distance between bends (DBB) and bend die radius (RC) being designated as known parameters, said tube bending machine being under the control of an automatic controller capable of directing said machine in predetermined sequential machine steps, particular sequences of machine steps being manually selectable by a human operator, the improvement comprising the steps of: calibrating said tube having machine and said automatic controller for the resilient characteristics of said tube material performing a calibration procedure including, manually activating said controller and machine to automatically execute at least two test bends with known test bend angles and bend radii, said test bend angles and bend radii being included in said known parameters, measuring the resultant bend angles and entering said resultant bend angles into said controller, said resultant bend angles being thereafter included in said known parameters, manually activating said controller and machine to automatically calculate a fixed springback compensation factor from said resultant bend angles, said known test bend angles, said known parameters and a given fixed springback compensation factor arithmetic relationship, and to calculate a radial springback compensation factor from said known parameters and a given radial springback compensation factor arithmetic relationship; deriving motion data to be executed by said machine and said controller by manually activating said controller to perform an automatic motion data derivation procedure including, calculating the radial springback compensation value from said radial springback compensation factor, said known parameters and a given radial springback compensation value arithmetic relationship, calculating the total radial and fixed springback compensation value from said radial springback compensation value, said fixed springback compensation factor and a given total radial and fixed springback compensation value arithmetic relationship, calculating a compensated distance between bends value from said known parameters, said total radial and fixed springback compensation value, and a given compensated distance between bends value arithmetic relationship, calculating an overbend angle from said known parameters and a given overbend angle arithmetic relationship.

Claim 3

The method defined in claim 1, including the step of: executing said derived motion data in accordance with an automatic execution procedure generated by said controller and executed by said machine.

Claim 4

The method defined in claim 1 wherein: said motion data deriving step includes testing said bend angle and bend radius for each bend to determine if said bend may be executed by a plurality of compensated incremental bends and using said incremental bends when possible.

Claim 5

The method defined in claim 3 including the step of: precomputing during said motion data deriving step the total length of tube material required to produce a tube of said specified shape by calculating a material arc length constant from said known parameters and a given arc length constant arithmetic relationship, said arc length constant relating a bend angle to the length of tube required for an associated bend and initially performing said motion data deriving step for each bend specified by said bend data and combining generated compensated distances between bends and overbend angles with the length of tube material required for the bends as determined by said material arc length constant.

Claim 6

The method defined in claim 3 wherein said testing step includes the automatically performed steps of: making a trial division of the given degree of bend angle by a trial number of incremental bends; comparing the resultant trial bend angle and calculated compensations for fixed and radial springback therefor with a bending machine configuration to be utilized; iteratively incrementing said trial number of incremental bends and performing said trial division and comparing steps until said comparing step indicates that the trial number of incremental bends cannot be performed by said machine configuration; and using a bend angle and associated compensations for a number of incremental bends which is one less than said trial number.

Claim 7

The method defined in claim 1 including: selectively and sequentially initiating said calibrating step and said motion data deriving step by a human operator responding to a sequence of questions and statements automatically generated by said controller and displayed by a display device.

Claim 8

The method defined in claim 6 including: storing the bend data for a plurality of different specified tube shapes and selecting a bend data for a desired specified tube shape by a human operator responding to an automatically displayed question therefor generated by said controller.

Claim 9

The method defined in claim 6 wherein: said motion data deriving step includes testing said bend angle and bend radius for each bend to determine if said bend may be executed by a plurality of compensated incremental bends and using said incremental bends when possible.

Claim 10

The method defined in claim 8 wherein said testing step includes the automatically performed steps of: making a trial division of the given degree of bend angle by a trial number of incremental bends; comparing the resultant trial bend angle And calculated compensations for fixed and radial springback therefor with a bending machine configuration to be utilized; iteratively incrementing said trial number of incremental bends and performing said trial division and comparing steps until said comparing step indicates that the trial number of incremental bends cannot be performed by said machine configuration; and using a bend angle and associated compensations for a number of incremental bends which is one less than said trial number.

Claim 11

In a method of bending a tube having substantially deformable and partially resilient material characteristics to a shape specified by given bend data consisting of, at least one bend angle with a given degree of bend (DOB) and a bend radius (RB), and straight distances between bends (DBB) with a tube bending machine having a bend die with a given bend die radius (RC), said given degree of bend (DOB), bend radius (RB), distance between bends (DBB) and bend die radius (RC) being designated as known parameters, said tube bending machine being under the control of an automatic controller capable of directing said machine in predetermined sequential machine steps, particular sequences of machine steps being manually selectable by a human operator, the improvement comprising the steps of: calibrating said tube bending machine and said automatic controller for the resilient characteristics of said tube material by manually inserting a test tube into said machine and performing a calibration procedure including, manually activating said controller and machine to automatically execute at least two test bends with known test bend angles and bend radii, said test bend angles and bend radii being included in said known parameters, measuring the resultant bend angles and entering said resultant bend angles into said controller, said resultant bend angles being thereafter included in said known parameters, manually activating said controller and machine to automatically calculate a fixed spring back compensating factor from said resultant bend angles, said known test bend angles, said known parameters and a given fixed spring back compensation factor arithmetic relationship, and to calculate a radial springback compensation factor from said known parameters and a given radial springback compensation factor arithmetic relationship; testing said given bend data for each bend to determine if said bend may be executed by a plurality of compensated incremental bends, said testing being performed by said controller in an automatic testing sequence including, making a trial division of the given degree of bend angle for each bend by a trial number of incremental bends, deriving motion data to be executed by said machine in said controller by manually activating said controller to perform an automatic motion data derivation procedure including, calculating the radial springback compensation value from said radial springback compensation factor, said known parameters and a given radial springback compensation value arithmetic relationship; calculating the total radial and fixed springback compensation value from said radial springback compensation value, said fixed springback compensation factor and a given total radial and fixed springback compensation value arithmetic relationship, calculating a compensated distance between bends value from said known parameters, said total radial and fixed springback compensation value, and a given compensated distance between bends value arithmetic relationship, calculating an overbend angle from said known parameters and a given overbend angle arithmetic relationship; comparing the resultant trial bend angle value and calculated compensation value for fixed and radial springback with said known parameters and a bending machine configuration to be used, iteratively incrementing said trial number of incremental bends and perForming said trial division, motion data derivation and comparing steps until said comparing step indicates that said trial number of incremental bends cannot be performed by said machine configuration and using a final bend angle value and associated compensation values for a total number of incremental bends one less than said trial number.

Claim 12

In a method of bending a tube having substantially deformable and partially resilient material characteristics to a shape specified by given bend data consisting of, at least one bend angle with a given degree of bend (DOB) and a bend radius (RB), and straight distances between bends (DBB) with a tube bending machine having a bend die with a given bend die radius (RC), said given degree of bend (DOB), bend radius (RB), distance between bends (DBB) and bend die radius (RC) being designated as known parameters, said tube bending machine being under the control of an automatic controller capable of directing said machine in predetermined sequential machine steps, particular sequences of machine steps being manually selectable by a human operator, the improvement comprising the steps of: calibrating said tube bending machine and said automatic controller for the resilient characteristics of said tube material by manually inserting a test tube into said machine and performing a calibration procedure including, manually activating said controller and machine to automatically execute at least two test bends with known test bend angles and bend radii, said test bend angles and bend radii being included in said known parameters, measuring the resultant bend angles and entering said resultant bend angles into said controller, said resultant bend angles being thereafter included in said known parameters, manually activating said controller and machine to automatically calculate a fixed spring back compensating factor from said resultant bend angles, said known test bend angles, said known parameters and a given fixed spring back compensation factor arithmetic relationship, and to calculate a radial springback compensation factor from said known parameters and a given radial springback compensation factor arithmetic relationship; testing said given bend data for each bend to determine if said bend may be executed by a plurality of compensated incremental bends, said testing being performed by said controller in an automatic testing sequence including, making a trial division of the given degree of bend angle for each bend by a trial number of incremental bends, deriving motion data to be executed by said machine in said controller by manually activating said controller to perform an automatic motion data derivation procedure including, calculating the radial springback compensation value from said radial springback compensation factor, said known parameters and a given radial springback compensation value arithmetic relationship; calculating the total radial and fixed springback compensation value from said radial springback compensation value, said fixed springback compensation factor and a given total radial and fixed springback compensation value arithmetic relationship, calculating a compensated distance between bends value from said known parameters, said total radial and fixed springback compensation value, and a given compensated distance between bends value arithmetic relationship, calculating an overbend angle from said known parameters and a given overbend angle arithmetic relationship; comparing the resultant trial bend angle value and calculated compensation value for fixed and radial springback with said known parameters and a bending machine configuration to be used, iteratively incrementing said trial number of incremental bends and perForming said trial division, motion data derivation and comparing steps until said comparing step indicates that said trial number of incremental bends cannot be performed by said machine configuration and using a final bend angle value and associated compensation values for a total number of incremental bends one less than said trial number.

Claim 13

The method defined in claim 10 including the step of: precomputing the total length of tube material required to produce a tube of said specified shape by calculating, during said calibrating step, a material arc length constant from said known parameters and a given arc length constant arithmetic relationship, said arc length constant relating a bend angle to the length of tube required for an associated bend and initially performing said trial division, motion data deriving, comparing, and incrementing steps to generate said operating commands and combining compensated distance between bends and overbend angles with calculated lengths of tube material required for the bends of said given bend data as determined by said material arc length constant.

Claim 14

The method defined in claim 11 including: displaying by automatic controller generated display sequence of tube material required to produce a tube of said specified shape.

Claim 15

The method defined in claim 10 including: storing the bend data for a plurality of different specified tube shapes and selecting the desired tube shape by human operator response to questions and statements automatically generated by said controller and displayed by a display device.

Claim 18

In a method of deriving motion data for use in bending a substantially deformable and partially resilient material characteristics to a shape specified by given bend data consisting of, at least one bend angle with a given degree of bend (DOB) and a bend radius (RB), and straight distances between bends (DBB) with a bending machine having a bend die with a given bend die radius (RC), said given degree of bend (DOB), bend radius (RB), distance between bends (DBB) and bend die radius (RC) being designated as known parameters, said tube bending machine being under the control of an automatic controller capable of directing said machine in predetermined sequential machine steps, particular sequences of machine steps being manually selectable by a human operator, the improvement comprising the steps of: calibrating said bending machine and said automatic controller for the resilient characteristics of said material by performing a calibration procedure including, manually activating said controller and machine to automatically execute at least two test bends with known test bend angles and bend radii, said test bend angles and bend radii being included in said known parameters, measuring the resultant bend angles and entering said resultant bend angles into said controller, said resultant bend angles being thereafter included in said known parameters, manually activating said controller and machine to automatically calculate a fixed springback compensation factor from said resultant bend angles, said known test bend angles, said known parameters and a given fixed springback compensation factor arithmetic relationship, and to calculate a radial springback compensation factor from said known parameters and a given radial springback compensation factor arithmetic relationship; deriving motion data to be executed by manually activating said controller to perform an automatic motion data derivation procedure including, calculating the radial springback compensation value from said radial springback compensation factor, said known parameters and a given radial springback compensation value arithmetic relationship, calculating the total radial and fixed springback compensation value from said radial springback compensation value, said fixed springback compensation factor and a given total radial and fixed springback compensation value arithmetic relationship, calculating a compensated distance between bends value from said known parameters, said total radial and fixed springback compensation value, and a given compensated distance between bends value arithmetic relationship, calculating an overbend angle from said known parameters and a given overbend angle arithmetic relationship.

Claim 19

In a method of deriving motion data for use in bending a substantially deformable and partially resilient material characteristics to a shape specified by given bend data consisting of, at least one bend angle with a given degree of bend (DOB) and a bend radius (RB), and straight distances between bends (DBB) with a bending machine having a bend die with a given bend die radius (RC), said given degree of bend (DOB), bend radius (RB), distance between bends (DBB) and bend die radius (RC) being designated as known parameters, said tube bending machine being under the control of an automatic controller capable of directing said machine in predetermined sequential machine steps, particular sequences of machine steps being manually selectable by a human operator, the improvement comprising the steps of: calibrating said bending machine and said automatic controller for the resilient characteristics of said material by performing a calibration procedure including, manually activating said controller and machine to automatically execute at least two test bends with known test bend angles and bend radii, said test bend angles and bend radii being included in said known parameters, measuring the resultant bend angles and entering said resultant bend angles into said controller, said resultant bend angles being thereafter included in said known parameters, manually activating said controller and machine to automatically calculate a fixed springback compensation factor from said resultant bend angles, said known test bend angles, said known parameters and a given fixed springback compensation factor arithmetic relationship, and to calculate a radial springback compensation factor from said known parameters and a given radial springback compensation factor arithmetic relationship; deriving motion data to be executed by manually activating said controller to perform an automatic motion data derivation procedure including, calculating the radial springback compensation value from said radial springback compensation factor, said known parameters and a given radial springback compensation value arithmetic relationship, calculating the total radial and fixed springback compensation value from said radial springback compensation value, said fixed springback compensation factor and a given total radial and fixed springback compensation value arithmetic relationship, calculating a compensated distance between bends value from said known parameters, said total radial and fixed springback compensation value, and a given compensated distance between bends value arithmetic relationship, calculating an overbend angle from said known parameters and a given overbend angle arithmetic relationship.