JP2002102929A - Bending method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To objectively measure an acute angle bending or an obtuse angle bending not through workers' hands by detecting an unilateral elongation value, an outer radius of a workpiece during bending. SOLUTION: During bending a workpiece, from a plurality of workpiece profile coordinate values (step S4) detected by a workpiece profile coordinate value detecting means and a workpiece plate thickness input in advance, a plurality of workpiece neutral axis coordinates are computed (step S10). By the sum of the distance between coordinates of plural workpiece neutral axes, the workpiece neutral axial length is computed (step S11). From a tangential intersecting point of both flanges of the workpiece by the workpiece profile coordinate values, a flange length is calculated (step S12). Based on the calculated flange length and the computed workpiece neutral axial length, the bending is executed while computing the elongation value of the workpiece (step S15).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending method and apparatus for detecting a one-sided elongation value and an outside radius R of a workpiece during bending of a plate-shaped workpiece.

[0002]

2. Description of the Related Art Conventionally, for example, in a press brake as a bending device, a punch and a die cooperate with each other.
When bending work is performed on a plate-shaped work, the one-sided elongation value of the work and the outside R of the work are unloaded after bending work,
It is measured by an operator using a measuring tool such as a caliper and a template.

[0003] For example, a one-sided elongation value is obtained by subtracting a developed dimension from a bending flange dimension measured by an operator.

[0004]

As described above, when obtaining a one-sided elongation value using a measuring tool, the more the one-sided elongation value becomes, the more complicated the bending shape becomes, such as a feed bending process. The calculation required is complicated and the detection time is long.

In the case of 90 ° bending, it is easy to measure the dimensions of the bending flange, but when the bending angle is an acute angle or an obtuse angle, it becomes very complicated, and it takes time and lacks accuracy. There was a problem.

[0006] Furthermore, since the operator presses a measuring tool such as a template against the bent portion to check the radius R outside the work, there is a problem that accuracy is lacking.

[0007] Further, there is a problem that both the one-sided elongation value and the outside radius of the work cannot be detected unless the load is unloaded after bending.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to detect a one-sided elongation value and an out-of-work radius during bending, and to perform any of acute angle bending and obtuse angle bending.
An object of the present invention is to provide a bending method and a device which can be measured objectively without depending on an operator.

[0009]

In order to achieve the above object, a bending method according to the present invention according to the first aspect of the present invention is a method of bending a workpiece in cooperation with a punch and a die. A plurality of workpiece neutral axis coordinates are calculated based on the sandwiching angle from a plurality of workpiece outer coordinate values of the workpiece detected by the means and a previously input workpiece plate thickness, and the sum of the distances between the plurality of workpiece neutral axis coordinates is calculated. Calculates the length of the workpiece neutral axis, calculates the flange length from the intersection of the tangents of both flanges of the workpiece based on the workpiece outer coordinate values, and calculates the workpiece length from the calculated flange length and the calculated workpiece neutral axis length. The bending process is performed while calculating the elongation value.

Therefore, during the bending process, the workpiece external coordinate values at a plurality of points at the bent portion of the workpiece are detected by using the workpiece external coordinate value detecting means, so that the neutral axis length of the workpiece and the flange length of the workpiece can be easily determined. Since the elongation value is easily and accurately calculated because the calculation is performed, there is no need for the operator to measure the work after bending.

According to a second aspect of the present invention, in the process of bending a work by cooperation of a punch and a die, a plurality of work outer coordinate values of the work detected by the work outer coordinate value detecting means are provided. The intersection of the lowermost coordinate value of the workpiece outer shape and the tangent line of both flanges is calculated based on the distance between the intersection and the lowermost coordinate value of the outer shape of the workpiece, and the bending angle of the workpiece. Is performed.

Therefore, the outside radius R of the work can be easily and accurately calculated by detecting the work outline coordinate values of a plurality of points at the bent portion of the work using the work outline coordinate value detecting means during the bending process. The elongation value in the acute angle bending can be easily calculated using the outside R of the work.

According to a third aspect of the present invention, in the process of performing a bending process on a workpiece by cooperation of a punch and a die, the die data, the workpiece data and the ram position detecting means stored in a memory in advance are used. Calculates the calculated work outline coordinate value from the detected ram stroke amount, and calculates the calculated work outline coordinate value and the work bend detected at a plurality of points in the work bending line direction by the work outline coordinate value detection means. Calculate the work die shoulder angle between the work and the die shoulder when this deviation is minimized from the deviation from the workpiece outer coordinate value of the part, and calculate the work die shoulder angle, mold data, and work data. Calculate the work die contact position where the work and the die are in contact, calculate the work flange length from the work die contact position, the work clamping angle and the plate thickness, and Kudai shoulder angle, mold data,
The length of the workpiece neutral axis is calculated from the workpiece data, and the bending is performed while calculating the elongation value of the workpiece from the calculated workpiece neutral axis length and the calculated flange length.

Therefore, when the deviation between the work outer coordinate value of the bent portion of the work and the calculated work outer coordinate value is minimized, an accurate work and a die shoulder can be obtained by the calculated work outer coordinate value. The work die shoulder angle is calculated. The work neutral axis length and the flange length are easily calculated from the work die shoulder angle, mold data, and work data, so that the single elongation value can be easily and accurately calculated. The trouble of measuring is eliminated.

According to a fourth aspect of the present invention, there is provided a bending apparatus for performing a bending process on a workpiece by cooperation of a punch and a die. A work outer shape coordinate value detecting means for detecting coordinate values, a memory for storing previously input mold data and work data, and a plurality of work outer shape coordinate values of the work detected by the work outer shape coordinate value detecting means; First workpiece neutral axis length calculating means for calculating a plurality of workpiece neutral axis coordinates from the sandwiching angle and the workpiece plate thickness, and calculating a workpiece neutral axis length by a sum of distances between the plurality of workpiece neutral axis coordinates; A first work flow which calculates a flange length from an intersection of tangents of both flanges of the work based on the work outer shape coordinate value detected by the work outer shape coordinate value detecting means. First elongation for calculating a work elongation value from a flange length calculating means, a flange length calculated by the work flange length calculating means, and a work neutral axis length calculated by the work neutral axis length calculating means. Value calculation means.

Accordingly, the operation is the same as that of the first aspect. During the bending process, the workpiece external coordinate values at a plurality of points of the bent portion of the workpiece are detected by using the external contour coordinate value detecting means of the workpiece, thereby making the workpiece neutral. Since the axial length and the flange length of the work are easily calculated, the single elongation value is easily and accurately calculated, so that the operator does not have to measure the work after bending.

According to a fifth aspect of the present invention, there is provided a bending apparatus for bending a workpiece by cooperation of a punch and a die. Work outline coordinate value detecting means for detecting coordinate values, a memory for storing previously input mold data and work data, and a work outline coordinate value for a plurality of points in the work detected by the work outline coordinate value detection means. A non-workpiece R calculation for calculating a non-workpiece R from a distance between the intersection and the tangent of the two flanges and a distance between the intersection and the tangent of the two pieces and a work bending angle. Means.

Therefore, the operation of the present invention is the same as that of the second aspect, and by detecting the external coordinates of the work at a plurality of points in the bent portion of the workpiece by using the external coordinates detection means during the bending, the external coordinates of the workpiece are detected. Since R is easily and accurately calculated, the elongation value in acute bending is easily calculated using the R outside the work.

According to a sixth aspect of the present invention, there is provided a bending apparatus for bending a work by cooperation of a punch and a die, comprising: a ram position detecting means for detecting a ram stroke amount; A work outer shape coordinate value detecting means for detecting a work outer shape coordinate value of a bent portion of the work in cooperation with the above, a memory for storing previously input mold data and work data, and the above mold data, work data, Work outer coordinate value calculating means for calculating the calculated work outer coordinate value from the ram stroke amount, and the work outer coordinate value calculated by the work outer coordinate value calculating means and detected by the work outer coordinate value detecting means. Work die shoulder angle calculator that calculates the work die shoulder angle between the workpiece and the die shoulder when the deviation from the workpiece outer coordinate value is minimized. If, Wakudai shoulder angle, die data obtained in this Wakudai shoulder angle calculating means,
Work die contact position calculation means for calculating a work die contact position at which the work and the die contact with the work data,
Second work flange length calculating means for calculating the work flange length based on the work die contact position, the work clamping angle and the plate thickness, and the work neutral axis length based on the work die shoulder angle, mold data, and work data. , The work neutral axis length calculated by the second work neutral axis length calculating means and the work flange length calculated by the second work flange length calculating means. And a second elongation value calculating means for calculating an elongation value of the workpiece by the above steps.

Therefore, when the deviation between the workpiece outer coordinate value of the bent portion of the workpiece and the calculated workpiece outer coordinate value is minimized, the calculated workpiece outer shape is obtained. Based on the coordinate values, an accurate work die shoulder angle between the work and the die shoulder is calculated. The work neutral axis length and the flange length are easily calculated from the work die shoulder angle, mold data, and work data, so that the single elongation value can be easily and accurately calculated. The trouble of measuring is eliminated.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIGS. 3 and 4, the press brake 1 as a bending device includes side frames 3L and 3R that are erected.
L and 3R have a notch G substantially at the center. In addition, an upper table 7 as a ram on which a punch P is mounted is provided at a lower end of the side frames 3L and 3R at a lower end portion via a plurality of intermediate plates 5 so as to be vertically movable.

Left and right ball screw units 9L and 9R, which are ram driving means for vertically moving the upper table 7, are provided on the upper front surfaces of the side frames 3L and 3R. In the ball screw units 9L and 9R, a ball screw (not shown) is rotationally driven by the drive motor 11 to move the upper table 7 up and down.

On the other hand, front and rear (left and right in FIG. 4) support plates 13F, 1F are provided on the lower front surfaces of the side frames 3L, 3R.
3R is provided, and a lower table 15 for mounting a die D at an upper end portion is sandwiched between upper portions of the front and rear support plates 13F and 13R. Further, both left and right ends of the lower table 15 are supported by fulcrum pins 17L, 17R which penetrate integrally with the support plates 13F, 13R and are fixed to the side frames 3L, 3R.

Therefore, both left and right ends of the lower table 15 are fixed vertically to the side frames 3L, 3R by the fulcrum pins 17L, 17R, but a slight vertical deformation is possible at the center.

The crowning means 19 for lifting the central portion of the lower table 15 with the left and right fulcrum pins 17L and 17R as fulcrums so that the central portions of the support plates 13F and 13R are in contact with the lower side of the lower table 15.
Is provided. Further, on the left side of the left side frame 3L in FIG. 3, a control device 21 for controlling the drive motor 11 and the like is provided.

At the position of the notch G of the side frames 3L and 3R, a back gauge device 23 for adjusting the bending position of the work W to the position of the punch P and the die D is provided. In the back gauge device 23, a plurality of abutments 25 for abutting the workpiece W are provided on the stretch 27, and the L-axis motor 29 causes the link mechanism 31 to move and position the stretch 27 in the L-axis direction (front-rear direction). It has become. When the Z-axis motor 33 is driven, the abutment 25 is moved in the Z-axis direction (up-down direction) via the link mechanism 31. Further, the Y-axis motor 3
By driving 5, the abutment 25 is moved in the Y-axis direction (the left-right direction in FIG. 5) by, for example, a rack and pinion drive mechanism.

With the above configuration, the butting 25 of the back gauge device 23 is moved in the L-axis, Y-axis, and Z-axis directions, positioned at a desired position, and the workpiece W is abutted against the butting 25. Next, the work W is bent in cooperation with the punch P and the die D.

As shown in FIG. 5, a plurality of slits 37 are provided at appropriate positions in the left-right direction of the die D so as to communicate with the die groove DV and have a plurality of slits 37 orthogonal to the longitudinal direction of the die groove DV. Formed within. A hole may be used instead of the slit 37. In the slit 37, that is, at a position deeper than the bottom of the die groove DV, as shown in FIG. With respect to the second plane orthogonal to the first plane with respect to the moving direction.

The back gauge device 23 is also used for abutting 2
5, a laser length measuring device 41 is provided as shown in FIG. The reflection mirror 39 and the laser length measuring device 41 constitute the work outer shape coordinate value detecting means 43. That is, the reflection mirror 39 is provided on the first plane and the second plane.
Is moved along a third plane orthogonal to the plane of.

With the above configuration, the laser length measuring device 41 is L
It is moved in the directions of the axis, the Y axis and the Z axis and positioned at a desired position. Moreover, the laser length measuring device 41
Is reflected by the reflection mirror 39 and then passes through the slit 37 to irradiate the bent portion on the side surface of the work W. Then, the irradiated laser light LB is returned to the laser length measuring device 41 as return light, and the distance from the laser length measuring device 41 to the side surface of the work W is detected. The reference position, which is the tip position of the laser length measuring device 41 in the L-axis direction, is previously set to a desired position by the L-axis motor 29.

The laser length measuring device 41 is connected to the Z-axis motor 33.
By moving and positioning in the Z-axis direction, the distance to both side surfaces of the work W is detected. Therefore, the coordinate values of a plurality of points of the curved shape in the bent portion of the work W are detected by using the detected distances to the both side surfaces of the work W.

The drive mechanism of the laser length measuring device 41 can be configured as shown in FIG. That is, a Y-axis drive motor 45 is provided on a bracket (not shown) attached to the lower table 15.
The shaft drive motor 45 includes a position detector 47 such as an encoder.
Is provided. In addition, one end of a ball screw 49 is connected to the output shaft of the Y-axis drive motor 45. A nut member 51 is screwed into the ball screw 49. The nut member 51 is provided with a Z-axis drive motor 53, and the Z-axis drive motor 53 is provided with a position detector 55 such as an encoder. In addition, one end of a ball screw 57 is connected to the output shaft of the Z-axis drive motor 53. A nut member 59 is screwed into the ball screw 57. The laser length measuring device 41 is integrated with the nut member 59.

The laser length measuring device 41 includes a light emitting device and a light receiving device, and the laser beam LB oscillated from the light emitting device.
The optical axis 1 of the work W is reflected by the reflection mirror 39 and is shown in FIG.
At the right side of the work W. Thereafter, the light is received by the light receiver as return light.

With the above configuration, when the Y-axis drive motor 45 is driven, the nut member 51 is moved in the Y-axis direction via the ball screw 49. The movement amount at that time is detected by the position detector 47. When the Z-axis drive motor 53 is driven, the nut member 59 is moved via the ball screw 57 in the Z-axis direction. The amount of movement at that time is determined by the position detector 55.
Is detected by

Therefore, the laser length measuring device 41 is moved in the Y and Z axis directions, and the amount of movement is determined by the position detector 4.
7, and 55 will be detected.

As shown in FIG. 7, the laser length measuring device 41 is sequentially moved and positioned at a constant distance, as shown by a two-dot chain line, at a constant distance.
By oscillating the optical axes 1, 2, 3, 4,..., N−1, n of B, the work W is irradiated on the side surface of the bent portion of the work W in FIG. 7. Thereafter, the light is received by the light receiver as return light. Therefore, the distances (Z ₁ , Y ₁ ) to the two side surfaces at a plurality of locations of the work W, (Z _{2
Y 2), ·····, (Z} n, Y n) is detected, details are stored in the distance memory 63 connected to the CPU61 of the control device 21 described later.

In FIG. 7, the Z-axis drive motor 53
When the position detector 55 is not provided, a plurality of protrudable stoppers can be provided at appropriate intervals in the Z-axis direction so that the laser length measuring device 41 can be moved and positioned.

The press brake 1 is provided with a ram position detecting means 65 for detecting a ram stroke amount. The ram position detecting means 65 is connected to the CPU 61 of the control device 21 as shown in FIG. In the present embodiment, a ball screw unit 9L,
For example, an encoder serving as a ram position detecting means 65 is attached to the drive motor 11 serving as a 9R rotation driving means. As another embodiment, when the ram drive unit is a hydraulic cylinder, a linear sensor for detecting the stroke of the ram is used as the ram position detection unit 65.

As shown in FIG. 8, the control device 21 includes an input means 67 such as a keyboard for inputting various data to a CPU 61 as a central processing unit, and a CRT for displaying various data. Display means 69 is connected. The Y-axis motor 35, the L-axis motor 29, and the Z-axis motor 33 are provided with encoders 71, 73, and 75, respectively, as position detectors.
It is connected to PU61.

Further, the CPU 61 has the die data inputted from the input means 67 as die data V, die shoulder radius DR, die groove angle DA, punch tip radius PR, punch angle PA, punch inclination length PL, As the work data, a memory 77 for storing bending conditions such as a plate thickness t, a friction coefficient μ, a work flange length L, and a finished angle θ, and a distance to a side surface of the work W detected by the laser length measuring device 41 are input. In addition, a distance memory 63 for storing the work outer coordinates at each measurement point is connected.

Further, the CPU 61 obtains a plurality of workpiece neutral axis coordinates from the plurality of workpiece outer coordinate values detected by the above-described workpiece outer coordinate value detecting means 43, the sandwiching angle and the workpiece plate thickness t. The first workpiece neutral axis length calculating means 79 for calculating the length of the workpiece neutral axis line based on the sum of the distances between the workpiece neutral axis coordinates, and the workpiece flange based on the workpiece external coordinate value detected by the workpiece external coordinate value detecting means 43. The first work flange length calculating means 81 for calculating the length, and the first elongation value calculating means 83 for calculating the elongation value of the work based on the work neutral axis length and the work flange length are connected.

The CPU 61 also stores a distance between the lowermost coordinate point of the work outer shape and the intersection of the two flange straight lines based on the work outer shape coordinate value detected by the work outer shape coordinate value detecting means 43, and a work bending angle. Is connected to a non-work R calculation means 85 for calculating a non-work R.

Next, a bending method according to the present invention will be described with reference to the flowcharts of FIGS.

The die V width V and the die shoulder radius D shown in FIG.
R, die groove angle DA, punch tip radius PR, punch angle PA, and punch inclination length PL are input and stored in the memory 77 (step S1).

Also, bending conditions such as plate thickness t and friction coefficient μ are input by the input means 67 as work data, and are stored in the memory 77 (steps S2 and S3).

Further, from the laser length measuring device 41 of the workpiece outer coordinate value detecting means 43, the optical axes 1, 2, 3,.
By oscillating i,..., n−1, n toward the bent portion of the work W, as shown in FIG. ₁ , y ₁ ), (x ₂ , y ₂ ),..., (X _i ,
y _i ),..., (x _n−1 , y _n−1 ), (x _n , y _n )
Is detected and stored in the distance memory 63 (step S
4).

When springback is not taken into account, the sandwiching angle is taken as θ, and when springback is taken into account, the finished angle is taken as θ.

The sandwiching angle can be obtained by various methods. For example, an approximate curve that matches the coordinate values of a plurality of points based on the coordinate values of the plurality of points obtained in step S4 is, for example, θ = ax in FIG. ^b + c (where θ: angle, x: position in x direction, a, b, c: unknown). A, b, and c are obtained from the coordinate values of a plurality of points.

[0050] Thus, when the x-coordinate of the workpiece W is in contact with the die D and _{x 0,} scissors angle theta ₂ of the workpiece W in the _{x 0 ^{is, θ 2 = ax 0 b +}} c ...... (1) x 0 = ( V / 2) + DR · tan (α / 2) − [(DR + t / 2)] · sin [(π−θ ₂ ) / 2] (2) where V = die groove width DR = die shoulder radius DA = die angle t = plate thickness α = (π−DA) / 2 According to the above two equations (1) and (2), the sandwiching angle θ ₂
Is required.

[0051] Therefore, if you do not consider springback, the theta = pinching angle theta ₂ (step S
5).

When springback is considered and the springback amount Δθ is known, the finished angle is θ, so that θ = sandwich angle A ₂ + springback amount Δθ, and each coordinate during bending is calculated. Are calculated after unloading (steps S7 and S9).

If the springback amount Δθ is not known, it is calculated based on Δθ = f ₁ (μ, t, V, DR, DA, PR, PA, PL) (3) (step S8) ).

Next, referring to FIG. 9, the coordinate values (x ₁ , y ₁ ), (x ₂ ,
y _{2), ...,} and _{(x i, y i),} ..., (x n, y n),
From the plate thickness t, the above-described step S6 or step S9
9, the neutral axis coordinates (x ′ ₁ , y ′) corresponding to the coordinate values of the plurality of points based on the angle θ obtained in
_{1), (x '2,} y' 2), ..., (x 'i, y' i),
..., is calculated by _{(x 'n, y' n} ) is the first work neutral axis length calculating unit 79 (step S10).

Further, the first workpiece neutral axis length calculating means
79, each neutral axis coordinate (x ′₁, Y '₁),
(X '₂, Y '₂), ..., (x '_i, Y '_i),…,
(X ' _n-1, Y '_n-1), (X '_n, Y '_n)Among
For example, l₁, L₂..., l_i..., l
_n-1The neutral axis length of the workpiece is calculated as
C is the sum of the above distances C = 1₁+ L₂+ ... + l_n-1To
Is calculated (step S11).

Next, the first work flange length calculating means 8
1, the coordinate values (x ₁ , y ₁ ), (x
_{2, y 2), ...,} (x i, y i), ..., (x n, y n)
When the intersection _{E (x} e, _y e) between the straight line _{L 1} and the straight line _{L 2} is an equation of the tangent line of the flanges from the flange length A, B are determined. That is, the flange length A is sought by calculating the distance between the _{G (x 1, y} 1) and _{E (x} e, _y e) in FIG. 9, the flange length B is I _(x n, y _n ) and the distance between E (x _e , y _e ) is calculated (step S12).

Next, the above-mentioned work outer coordinate values (x ₁ , y ₁ ), (x ₂ ,
y ₂ ),..., (x _i , y _i ),..., (x _n , y _n ), coordinate point F (x _f , y _f ) at the lowest point on the y-axis and point E (x _e , Y _e ) is calculated (step S13).

Therefore, R outside the work is sin (θ / 2) = outside R / (outside R + H) in ΔOEG in FIG.
Therefore, based on this formula, based on this formula, R = H · {sin (θ / 2) / [(1−sin (θ / 2)]} (4) where θ: in step S6 or step S9 The obtained bending angle is calculated by the above equation (4) (step S
13).

Next, when the bending angle θ is 90 ° or an obtuse angle, the one elongation value is calculated by the first elongation value calculating means 83 as follows: one elongation value = (A + BC) / 2 (5) , A, B: Length of both flanges obtained in step S12 C: Length of neutral axis obtained in step S11 Calculated by the above equation (5) (steps S14 and S
15).

When the bending angle θ is an acute angle, the first elongation value calculating means 83 calculates the half-elongation value as follows: half-elongation value = (A + BC−2D) / 2 (6) , B = length of both flanges obtained in step S12 C = length of neutral shaft obtained in step S11 D = [outside R / tan (θ / 2)] − outside R The above equation (6) (Steps S14 and S1)
6 and S17).

As described above, by detecting the coordinate values of a plurality of points of the bent portion of the work W using the work outer shape coordinate value detecting means 43 during the bending, the one-sided extension value and the outside of the work are detected during the bending. R is easily and accurately calculated and detected. Therefore, the labor for the worker to measure the workpiece W after the bending can be saved.

Next, a bending apparatus according to another embodiment of the present invention will be described with reference to the drawings. The description of the same parts as those of the bending apparatus of the above-described embodiment will be omitted, and only different parts will be described.

Referring to FIG. 8, the control device C
The PU 61 includes a work outer coordinate value calculating means 87 for calculating a calculated work outer coordinate value from the mold data, work data, bending force, and ram stroke amount stored in the memory 77; The difference between the work W and the die shoulder when the deviation between the work outer coordinate value calculated by the arithmetic means 87 and the work outer coordinate value detected by the work outer coordinate value detecting means 43 is minimized. and Wakudai shoulder angle calculating means 89 for calculating a die shoulder angle phi ₂ is connected.

The CPU 61 calculates the position where the work W and the die D are in contact with each other based on the work die shoulder angle φ ₂ calculated by the work die shoulder angle calculating means 89, the mold data, and the work data. Work die contact position calculating means 91; second work flange length calculating means 93 for calculating the flange length of the work W based on the work die contact position, the clamping angle of the work W and the plate thickness; work die shoulder angle, die Second work neutral axis length calculating means 95 for calculating a work neutral axis length based on data and work data; and second work neutral axis length calculating means 95
The second elongation value calculation means 97 for calculating the elongation value of the work W based on the work neutral axis length calculated by the above and the work flange length calculated by the second work flange length calculation means 93 is connected. .

Next, a bending method according to another embodiment of the present invention will be described with reference to flowcharts shown in FIGS.

The die V width V and the die shoulder radius D shown in FIG.
R, die groove angle DA, punch tip radius PR, punch angle PA, and punch inclination length PL are input and stored in the memory 77 (step S21).

Further, bending conditions such as a plate thickness t and a friction coefficient μ are input by the input means 67 as work data (steps S22 and S23).

In the present embodiment, the ram stroke amount St is detected from the encoder of the drive motor 11 by the ram position detecting means 65 and is input to the control device 21.

Further, the work external coordinate value detecting means 43
, I,..., N−
1, n is oscillated toward the bent portion of the work W
As a result, a plurality of curved shapes in the bent portion of the workpiece W
Point coordinates (x₁, Y₁), (X₂, Y₂), ..., (x
_i, Y_i), ..., (x_n-1, Y_n-1), (X_n, Y
_n) Is detected and stored in the distance memory 63 (step
S24).

Based on the arithmetic expression input in advance and stored in the memory 77, the work W
The calculated value of the n value, which is the material constant, and the calculated work outer coordinate value are obtained by the work outer coordinate value calculation means 87, and as shown in FIG. 10, the work W and the die shoulder during bending are formed. The calculated value of the work die shoulder angle φ ₂ is obtained by the work die shoulder angle calculation means 89. The details will be described below.

The relational expression between the ram stroke amount St and the mold data, work data, n value and φ ₂ is as follows: St = f ₁ (φ ₂ , n, μ, t, V, DR, DA, PR, PA) (21) First, let k = 0 as the constant k, set the φ ₂ limit value based on PA and DA, and set dφ ₂ (eg, 0.5
°), coordinate error err is set to err = 0, and φ ₂
Is assumed to be the initial value φ _0, and when these values are input to the above equation (21), the n value is calculated (step S
25-S27).

As described above, based on the calculated value of the n value when φ ₂ is assumed to be the initial value φ ₀ ,
In 4, the calculated y ′ _i coordinate value of the _xi coordinate value corresponding to the measurement point measured by the work outer shape coordinate value detecting means 43 is obtained by the work outer shape coordinate value calculating means 87.

X _i = f ₂ (φ, φ ₂ , n, μ, t, V, DR, DA, PR, PA) (22) where x _i ; the i-th x coordinate of the measured bending shape phi; because it is the inclination angle of the workpiece W in the x _i, the angle phi is calculated in xi coordinate values shown in Figure 15 based on the calculation formula (2) (step S28).

Further, y ′ _i = f ₃ (φ, φ ₂ , n, μ, t, V, DR, DA, PR, PA) (23) where y ′ _i ; Since it is the calculated value of the y coordinate, y ′ _i is calculated based on the operation formula (22) (step S29).

[0075] Thus, the measured value of the y coordinate by the workpiece contour coordinate value detecting means 43 at the measurement point x _i, as shown in FIG. 15 is a y _i, since the y _'i is computationally, phi ₂ is The coordinate error at the measurement point x _i assuming the initial value φ ₀ and the calculated value of the n value is err _i = | y _i −y ′
_i |. Therefore, the accumulated error at the measurement point x _i is err = err + err _i (step S30).

By repeating the above steps S28 to S31, the calculated coordinate values corresponding to all the measured coordinates and the total coordinate error err of each coordinate are obtained (step S3).
1).

Therefore, when φ ₂ is assumed to be the initial value φ ₀ and the calculated value of the n value, the overall coordinate error _k in the calculated coordinate values corresponding to all the measured coordinates is obtained as err (step S32).

This error dφ set in step S26
_The calculated φ ₂ taking into account ₂ is φ ₂ = φ ₂ + dφ ₂ , and when the constant k = 0, φ ₂ = φ ₀ + dφ ₂ (step S 33).

Further, 1 is added to the above-mentioned constant k to calculate as a constant k = k + 1 (step S34).

The calculated φ ₂ obtained in step S33 is compared with the φ ₂ limit value (step S35), and φ ₂
Is smaller than the limit value, err value of coordinate error _k calculated in step _{S32~S34, φ 2 (= φ 2} + d
φ ₂ ) and k (= k + 1) are substituted into the operation expression (1) in step S27, and the n value is calculated. Hereinafter, steps S28 to S34 are similarly repeated.

Again, in step S35, step S3
The calculated φ obtained in 3₂Is φ₂Compared to the limit value.
Calculated φ₂Is φ₂Coordinates when greater than limit
error _kΦ when is minimized₂Ask for. In other words, the figure
At 15, the calculated coordinate value of the work W and the
The coordinate values measured by the outer shape coordinate value detecting means 43 are
It is determined that they match, and at this time the work die shoulder angle
Φ calculated by the calculating means 89₂Becomes the ram stroke amount St
Judgment is the actual work die shoulder angle of work W
And the value of n at this time is determined (s
Step S36).

Next, based on the sandwiching angle θ and the shape of the mold, the coordinates B of the neutral axis at which the workpiece W contacts the die D during bending.
₀ (x ₀ , y ₀ ) is geometrically calculated.

Referring to FIG. 16, the coordinates B ₀ (x ₀ , y
₀ ) is x ₀ = L− (DR + t / 2) · sin φ ₂ y ₀ = Y− [DR− (DR + t / 2) · cos φ ₂ ] where L = V / 2 + DR · tan α / 2 α = (π−DA ) / 2.

Therefore, x ₀ is calculated from x ₀ = V / 2 + DR · tan α / 2− (DR + t / 2) · sin φ ₂ (24) (step S37).

Next, when springback is not taken into account, the sandwiching angle is set to θ, and when springback is taken into account, the finished angle is set to θ.

The sandwiching angle θ is determined in step S36.
Given by θ = π-2φ ₂ based on phi ₂ obtained in (Step S39).

When springback is taken into consideration, when the springback amount Δθ is known, the finished angle is θ, so that θ = clamping angle + springback amount Δθ. The coordinates after loading are calculated. At this time, a corresponding numerical value from a database stored in the memory 77 in advance is used as the springback amount Δθ (steps S40 and S41).
And S44).

If the springback amount Δθ is not known, the Young's modulus E of the database is used, and Δθ = f ₄ (φ ₂ , n, F, Eμ, t, V, DR, DA, PR, PA ) (25) (Steps S40, S42 and S42)
43).

[0089] Furthermore, when considering the spring-back, x after spring back points in contact with the die D in a value applicable bending a x ₂ considered in step S37
Coordinates are used. For example, when the angle between the workpiece W and the die shoulder portion after springback is _{φ '2, x 0 = V} / 2 + DR · tanα / 2- (DR + t / 2) · s
inφ _'2 and made (step S45).

Next, the dimensions of the flange of the work W in the mold are calculated. In this embodiment, when both flange lengths A and B in FIG. 9 are calculated assuming that A = B, the flange length A (or B) is A = x ₀ / cos [(π−θ) / 2] + (t / 2) · tan [(π−θ) / 2] (26) (step S46).

The length C of the neutral axis is calculated from C = f ₅ (φ ₂ , n, μ, t, V, DR, DA, PR, PA) (27) (step S 47) .

Next, as shown in FIG. 9, the outside-work-R calculating means 85 outputs the work external coordinate value detecting means 43.
Work coordinate values (x ₁ , y ₁ ), (x
_{2, y 2), ...,} (x i, y i), ..., (x n, y n)
Y-axis lowest point coordinate point F in the _(x f, _{y f)} and, above E
The distance H between the point (x _e , y _e ) is calculated.

Accordingly, the outside radius R of the work is calculated by the following equation (4) in the above-described embodiment: R = H · {sin (θ / 2) / [(1−sin (θ / 2)]} (4) Here, θ is calculated based on the bending angle obtained in step S39 or step S44 (step S48).

Next, when the bending angle θ is 90 ° or an obtuse angle, the second elongation value calculating means 97 calculates
Since A = B according to the equation (5) in the above-described embodiment, the one-sided elongation value = (2A−C) / 2 (5) where A is the length of both flanges obtained in step S46. It is calculated with the length of the neutral axis obtained in S47 (steps S49 and S50).

When the bending angle θ is an acute angle, the second elongation value calculating means 97 determines that the half elongation value is A = B according to the equation (6) in the above embodiment. 2A-C-2D) / 2 (6) where A = length of both flanges obtained in step S46 C = length of neutral shaft obtained in step S47 D = [outside R / tan ( θ / 2)] − outside R (steps S49, S51 and S52).

As described above, as in the case of the above-described embodiment, during the bending process, the work external coordinate value detecting means 4 is used.
By detecting the coordinate values of a plurality of points of the bent portion of the work W using the method 3, the one-sided elongation value and the outside R of the work are easily and accurately calculated and detected during the bending. Therefore, the labor for the worker to measure the workpiece W after the bending can be saved.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0098]

As will be understood from the above description of the embodiments of the present invention, according to the first aspect of the present invention, during the bending process, the bending portion of the workpiece is detected by using the workpiece outer coordinate value detecting means. Since the workpiece outer coordinate values at multiple points are detected, the neutral axis length of the workpiece and the flange length of the workpiece can be easily calculated, so that the single elongation value can be calculated easily and accurately. The trouble of measuring can be eliminated.

According to the second aspect of the present invention, during the bending,
Since the work outline coordinate values of a plurality of points at the bent portion of the work are detected by using the work outline coordinate value detection means, the outside of the work R
Can be easily and accurately calculated. Further, the elongation value in the acute angle bending can be easily calculated using the outside R of the work.

According to the third aspect of the present invention, when the deviation between the outer shape coordinate value of the work at the bent portion of the work and the calculated outer shape coordinate value of the work is minimized, the calculated outer shape coordinate value of the work is accurate. The work die shoulder angle between the workpiece and the die shoulder can be calculated.
The neutral axis length and the flange length of the workpiece can be easily calculated based on the mold data and the workpiece data, the one-side elongation value can be easily and accurately calculated, and the labor for measuring the workpiece after bending can be eliminated.

According to the fourth aspect of the present invention, it is the same as the effect of the first aspect, and the workpiece outer coordinate values at a plurality of points of the bent portion of the workpiece are determined by using the workpiece outer coordinate value detecting means during the bending. Since it is detected, the neutral axis length of the work and the flange length of the work can be easily calculated, so that the one-sided elongation value can be easily and accurately calculated, and the labor for the worker to measure the work after bending can be eliminated. .

According to the fifth aspect of the present invention, it is the same as the effect of the second aspect, and the work outer coordinate values of a plurality of points of the bent portion of the work are determined by using the work outer coordinate value detecting means during the bending. Since it is detected, R outside the work can be easily and accurately calculated. Further, the elongation value in the acute angle bending can be easily calculated using the outside R of the work.

According to the sixth aspect of the invention, the effect is the same as that of the third aspect, and when the deviation between the work outer coordinate value of the bent portion of the work and the calculated work outer coordinate value is minimized. The work die shoulder angle between the work and the die shoulder can be calculated accurately based on the calculated work outline coordinate values.The work neutral axis length and flange length can be calculated based on the work die shoulder angle, mold data, and work data. Can be easily calculated, the one-sided elongation value can be easily and accurately calculated, and the labor for the operator to measure the workpiece after bending can be eliminated.

[Brief description of the drawings]

FIG. 1 is a flowchart of a bending method according to an embodiment of the present invention.

FIG. 2 is a flowchart subsequent to FIG. 2 of the bending method according to the embodiment of the present invention.

FIG. 3 is a front view of a press brake as a bending machine according to the embodiment of the present invention.

FIG. 4 is a right side view in FIG.

FIG. 5 is a front view of a die according to the embodiment of the present invention.

FIG. 6 is a schematic side view of a work outer shape coordinate value detection unit according to the embodiment of the present invention.

FIG. 7 is a schematic explanatory view of a work outer shape coordinate value detecting means in the embodiment of the present invention.

FIG. 8 is a configuration block diagram of a control device.

FIG. 9 is an explanatory diagram of a state of a workpiece to be bent.

FIG. 10 is an explanatory diagram of each part when being bent by a punch and a die.

FIG. 11 is a flowchart of a bending method according to another embodiment of the present invention.

FIG. 12 is a flowchart following FIG. 11 of a bending method according to another embodiment of the present invention.

FIG. 13 is a flowchart of a bending method according to another embodiment of the present invention, which is subsequent to FIG. 12;

FIG. 14 is a flowchart of a bending method according to another embodiment of the present invention, which is subsequent to FIG. 13;

FIG. 15 is an explanatory diagram of a state when bending is performed by a punch and a die.

FIG. 16 is an explanatory diagram of a state on the right side from the center when bending is performed by a punch and a die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Press brake 7 Upper table 9 Ball screw unit 11 Drive motor 15 Lower table 21 Control device 39 Reflection mirror 41 Laser length measuring device 43 Work outline coordinate value detection means 63 Distance memory 65 Ram position detection means 77 Memory 79 First work neutral axis length Depth calculation means 81 First work flange length calculation means 83 First extension value calculation means 85 Outside work R calculation means 87 Work outside coordinate value calculation means 89 Work die shoulder angle calculation means 91 Work die contact position calculation means 93 Second flange length Length calculation means 95 Second work neutral axis length calculation means 97 Second extension value calculation means

Claims (6)

[Claims] In a process of bending a work by cooperation of a punch and a die, a work outer shape coordinate value of a plurality of points on a work detected by a work outer shape coordinate value detecting means and a work thickness previously input are used. A plurality of work neutral axis coordinates are calculated based on the sandwiching angle, a work neutral axis length is calculated by a sum of distances between the plurality of work neutral axis coordinates, and a tangent of both flanges of the work based on the work outer shape coordinate value is calculated. A bending method comprising calculating a flange length from an intersection, and performing bending while calculating a work elongation value from the calculated flange length and the calculated work neutral axis length. 2. A process for bending a workpiece by cooperation of a punch and a die, wherein the lowermost coordinate value of the outer shape of the workpiece is determined based on the outer shape coordinate values of a plurality of points on the workpiece detected by the workpiece outer coordinate value detecting means. A bending method comprising calculating an intersection of tangents of both flanges, and performing bending while calculating a radius R outside the work from a distance between the intersection and the coordinate value of the lowermost end of the work outer shape and a bending angle of the work. . 3. In the process of bending a work by cooperation between a punch and a die, a calculation is performed on the basis of mold data and work data previously stored in a memory, and a ram stroke amount detected by a ram position detecting means. The outer shape coordinate value of the work is calculated, and the deviation between the calculated outer shape coordinate value of the work and the outer shape coordinate value of the bent portion of the work detected at a plurality of positions in the bending line direction of the work by the work outer shape coordinate value detecting means. From this, calculate the work die shoulder angle between the work and the die shoulder when this deviation is minimized, and determine the work die contact position where the work and the die make contact with this work die shoulder angle, mold data, and work data. Calculate and calculate the flange length of the work from the contact position of the work die, the sandwiching angle of the work and the plate thickness, the work die shoulder angle, the mold data, the work Calculating a workpiece neutral axis length by chromatography data, bending method and performing bending while calculating the elongation value of a work from the flange length this was computed and the workpiece neutral axis length is the arithmetic. 4. A bending apparatus for bending a work by cooperation between a punch and a die, wherein a work outline coordinate value detection for detecting a work outline coordinate value of a bent portion of the work by cooperation between the punch and the die. Means, a memory for storing previously input mold data and work data, and a plurality of work outline coordinate values of a plurality of points in the work detected by the work outline coordinate value detection means, a sandwich angle, and a work plate thickness. Work neutral axis coordinates are calculated, and the first work neutral axis length calculating means for calculating the work neutral axis length based on the sum of the distances between the plurality of work neutral axis coordinates, and the work external coordinate value detecting means are detected. First work flange length calculating means for calculating the flange length from the intersection of the tangents of both flanges of the work based on the work outer shape coordinate value; A first elongation value calculating means for calculating a work elongation value from the flange length calculated by the jig length calculating means and the work neutral axis length calculated by the work neutral axis length calculating means. A bending apparatus characterized by the above-mentioned. 5. A bending apparatus for bending a work by cooperation of a punch and a die, wherein a work outer coordinate value detection for detecting a work outer coordinate value of a bent portion of the work by the cooperation of the punch and the die. Means, a memory for storing previously input mold data and work data, and a work outermost coordinate value based on the work outer coordinate values of a plurality of points in the work detected by the work outer coordinate value detecting means. A non-work R calculating means for calculating an intersection of tangents of the flange, calculating a non-work R from a distance between the intersection and the coordinate value of the lowermost end of the work outer shape, and a bending angle of the work. And bending equipment. 6. A bending apparatus for bending a work by cooperation of a punch and a die, comprising: a ram position detecting means for detecting a ram stroke amount; and a bending section of the work by the cooperation of the punch and the die. Work outer shape coordinate value detecting means for detecting the work outer shape coordinate value, a memory for storing previously input mold data and work data, and work outer shape coordinates calculated from the above mold data, work data and ram stroke amount A work outer coordinate value calculating means for calculating a value; and a deviation between the work outer coordinate value calculated by the work outer coordinate value calculating means and the work outer coordinate value detected by the work outer coordinate value detecting means is minimum. Work die shoulder angle calculating means for calculating a work die shoulder angle between the workpiece and the die shoulder when the work die is formed, and the work die shoulder angle calculating means A work die contact position calculating means for calculating a work die contact position at which the work and the die come into contact with each other, based on the work die shoulder angle, mold data, and work data obtained in the above step; Second work flange length calculating means for calculating the work flange length, and second work neutral axis length calculating means for calculating the work neutral axis length based on the work die shoulder angle, mold data, and work data. A second elongation value for calculating a work elongation value based on the work neutral axis length calculated by the second work neutral axis length calculation means and the work flange length calculated by the second work flange length calculation means. And a calculating means.