JP3444679B2 - Bending method and apparatus - Google Patents

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 an apparatus for bending a work so that the bending load is made uniform with respect to the bending length of the work so that the bending accuracy is good. .

[0002]

2. Description of the Related Art Conventionally, as a press brake as a bending apparatus, (A) a punch provided on an upper table via a plurality of intermediate plates, and a die provided on a vertically movable lower table. (B) A punch provided on the upper table and a die provided on the lower table that can move up and down through a plurality of intermediate plates. (C) A punch provided on the upper table and a die controlled by a hydraulic cylinder mechanism provided inside a vertically movable lower table cooperate with each other. A type in which a work is bent is generally known.

[0003]

By the way, in the above-mentioned conventional press brake, in order to improve the bending accuracy with respect to the bending length of the work, the above (A),
In the type (B), the wedge mechanism of each intermediate plate is manually operated and adjusted, and in the type (C), the pressure of the hydraulic cylinder mechanism is adjusted, but the adjustment is bothersome.

Further, the correction amount required for the adjustment is not clear in any of the forms, and it is necessary to repeat the trial bending while relying on the intuition of the operator. Further, even if the required correction amount can be obtained, the appropriate correction amount also changes when the bending position and the bending length change, and thus it is not possible to easily perform correction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bending method and an apparatus therefor in which a proper correction amount is always easily obtained even when a bending position and a bending length of a work are changed to improve bending accuracy. is there.

[0006]

In order to achieve the above object, the bending method of the invention according to claim 1 is a punch provided on an upper table via a plurality of intermediate plates, and a lower table movable up and down. The bending method for bending the work in cooperation with the die provided in the, and the load value of each intermediate plate being bent is detected by the load detection means provided in each intermediate plate. The slope of a predetermined range of the elastic region or the maximum value of the plastic region in the load diagram of the punching amount or the thrusting time of the punch with respect to the die and the load value of each of the intermediate plates and the load of the inclination or the maximum value are obtained. A feature that the distribution ratio is obtained, and then the work is bent so that the load distribution ratio of each intermediate plate at the target bending angle is controlled so as to be the load distribution ratio of the inclination or the maximum value. A.

The bending apparatus of the invention according to claim 2 is
A bending apparatus for bending a work by cooperation of a punch provided on an upper table via a plurality of intermediate plates and a die provided on a vertically movable lower table,
Load detecting means provided on each of the intermediate plates, a position sensor for detecting a moving position of the die with respect to the punch, a load value detected by the load detecting means, and a plunge amount or plunge time detected by the position sensor. And a first calculation means for obtaining the maximum value of the plastic region or the inclination of a predetermined range of the elastic region in the load diagram and the inclination or the maximum value based on the slope or the maximum value obtained by the first calculation means. The second calculation means for obtaining the load distribution ratio of the intermediate plate and the load distribution ratio of each intermediate plate at the target bending angle are controlled so that the load distribution ratio of the inclination or the maximum value obtained by the second calculation means is controlled. A correction means for correcting the table or each intermediate plate is provided.

[0008]

According to the bending method and the apparatus therefor according to claims 1 and 2, the punch provided on the upper table via the plurality of intermediate plates and the lower table movable up and down are provided. The work is bent in cooperation with the die.

During bending of the workpiece, the load value of each intermediate plate is detected by the load detecting means provided on each intermediate plate, and the moving position of the die with respect to the punch is positioned. A load diagram which is detected by the sensor and which is obtained by detecting the plunge amount or plunge time and the intermediate load values is obtained. The inclination of a predetermined range of the elastic region or the maximum value of the plastic region in each load diagram is obtained by the first calculating means.

On the basis of the inclination or the maximum value obtained by the first calculating means, the load distribution ratio of the inclination or the maximum value is obtained by the second calculating means. The load distribution ratio of the inclination or the maximum value obtained by the second calculating means and the load distribution ratio of each intermediate plate at the target bending angle which can be seen from the load diagram are fetched by the correcting means, and each of the target bending angles is obtained. The correction amount is calculated so that the load distribution ratio of the intermediate plate becomes the load distribution ratio of the inclination or the maximum value, and the bending position and bending length of the work are controlled by controlling each intermediate plate or the lower table by this correction amount. Regardless of the size, the bending process is performed with good accuracy in bending.

[0011]

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

Referring to FIG. 4, a press brake 1 as a bending device is provided with an upright side frame 3, and an upper table 5 is fixedly provided on the front upper part of the side frame 3. ing. A punch 9 is provided below the upper table 5 via a plurality of intermediate plates 7 provided at appropriate intervals in the left-right direction.

A vertically movable lower table 11 is provided on the front side of the side frame 3, and a die 13 corresponding to the punch 9 is provided above the lower table 11. Main cylinders 15L and 15R are disposed below the left and right sides of the lower table 11, and the tip ends of piston rods 17L and 17R attached to the main cylinders 15L and 15R are attached to the lower table 11. In addition, the lower table 11
A plurality of crowning cylinders 19 are provided inside, and a piston rod 21 mounted on the crowning cylinders 19 is attached to the lower table 11. A position sensor 22 is provided on the side of the die 13 and the punch 9. That is, the sensor 22A is provided on the side of the die 13 and the detected portion 22B is provided on the side of the punch 9.
Are provided correspondingly.

With the above structure, the main cylinder 15L,
When 15R is operated, piston rods 17L, 17L
When the lower table 11 is moved up and down through the R, the work fixed on the die 13 is bent by the cooperation of the punch 9 and the die 13.
The position of the die 13 with respect to the punch 9 is detected by the position sensor 22. Further crowning cylinder 19
Is operated to move the piston rod 21 up and down, the crowning of the die 13 can be corrected.

A load detecting means 23 such as a strain gauge or a piezo element is provided inside each of the intermediate plates 7, and the load of the intermediate plate 7 during bending is detected.
The load detecting means 23, main cylinders 15L, 15R
Further, the crowning cylinder 19 is connected to an NC device 27 as a control device provided on the upper table 5 via a bracket 25, respectively.

Each intermediate plate 7 is provided with intermediate plate adjusting means 28. That is, as shown in FIG. 5, the upper table 5 is provided with ball screws 29 which are rotated in the left-right direction (direction orthogonal to the paper surface in FIG. 5) by a drive motor (not shown). A fork-shaped member 31 is screwed onto the ball screw 29. Further, below the ball screw 29, the upper table 5 is provided with a drive shaft 33 which is rotated in parallel with the ball screw 29 by a drive motor (not shown). A ball spline is provided on the outer periphery of the drive shaft 33. The drive gear 35 which is cut and is moved by the fork-shaped member 31 is fitted and attached thereto. Another gear 37 is meshed with the drive gear 35.

Referring also to FIG. 6, each intermediate plate 7 is provided with a wedge member 41 for adjusting the vertical distance between the upper table 5 and the punch 9 in the recess 39 at the upper portion thereof. In FIG. 5, an adjusting screw shaft 43 is screwed on the wedge member 41 to move it in the left-right direction. The adjusting screw shaft 43 of each of the intermediate plates 7 is configured to be located on the same straight line.

As shown in FIG. 6, the lower surface of the upper table 5 and the upper surface of the wedge member 41 are in contact with each other in a horizontal plane, and the lower surface of the wedge member 41 and the upper surface of the recess 39 of the intermediate plate 7 are inclined. They are in contact with each other. The adjusting screw shaft 43 is screwed in the central portion of the wedge member 41, and both ends thereof are supported by ball bearings 45 provided on the intermediate plate 7.

As shown in FIG. 5, each intermediate plate 7 is attached to the lower end of the upper table 5 by a support plate 47, a clamp 49, a hydraulic device 51, a presser foot 53, etc. The punch 9 is attached to the lower portion by a clamp 55.

The reference position of the wedge member 41 is, as shown in FIG. 6, the detector 5 provided at the left end of the ball bearing 45.
Detected by 7. Further, as shown in FIG. 5, an information element 59 is embedded in the intermediate plate 7, and an antenna 61 attached to the fork-shaped member 31.
However, they are facing each other with a certain distance.

With the above structure, the drive gear (not shown) moves the drive gear 35 to the position of the intermediate plate 7 to be adjusted, meshes with the gear 37, and then the hydraulic pressure of the hydraulic device 51 is released to loosen the intermediate plate 7. Next, the wedge member 41 is moved until it comes into contact with the detector 57 by a drive motor (not shown) to set a reference position, and then a pulse number corresponding to a predetermined adjustment amount is supplied to the drive motor (not shown) from this position. Wedge member 41
And then apply hydraulic pressure to the hydraulic device 51 to move the intermediate plate 7
Is fixed. The other intermediate plates 7 are similarly adjusted and adjusted. The position number and adjustment amount of each intermediate plate 7 are stored in the information element 59.

Therefore, the punch 9 and the die 13 are attached to the work.
When performing bending work in cooperation with
The load applied to each intermediate plate 7 is detected by the load detecting means 23 provided in the. Each of the detected loads is the NC device 27.
Is corrected by the NC device 27 so that the bending angle in the bending length is made uniform, that is, the bending accuracy is improved. By this correction processing, each intermediate plate 7 is adjusted, or position commands are issued to the main cylinders 15L and 15R, and the crowning cylinder 19 is moved.
The pressure command is given to the and the bending is performed with good bending accuracy.

As shown in FIG. 1, the NC device 27 is provided with a CPU 63, which is connected to an input means 65 for inputting various data and conditions. Output means 67 for outputting the output is connected. Further, each load detecting means 23 is connected to the CPU 63 so that each load detected by each load detecting means 23 is taken in and the thrust amount (time) detected by the position sensor 22 is measured. ) Is being taken in.

An intermediate plate, a load diagram, and a memory 69 are connected to the CPU 63. This intermediate plate / load diagram / memory 69 stores the load value of each intermediate plate 7 detected by each load detecting means 23 and the thrust amount (time) detected by the position sensor 22 and is shown in FIG. The load diagram as shown is stored. In the stored load diagram, it becomes a straight line in the elastic region of the work, has a maximum value at a bending angle of about 120 degrees, and ends bending at a bending angle of about 90 degrees.

Based on the intermediate plate / load diagram / intermediate plate / load diagram stored in the memory 69, the first computing means 71 connected to the CPU 63 bends the intermediate plate 7 in the load diagram. The inclination of the elastic region is shown in FIG.
_{1, A 2, A 3,} ···, obtained in _{A i),} further the inclination
The total sum _AT of the mushrooms is calculated as follows.

[0026]

[Equation 1] Alternatively, the maximum value (B ₁ , B ₂ , B ₃ , ..., B _i ) of the plastic region in the load diagram of each intermediate plate 7 is obtained, and the total sum is calculated as follows.

[0027]

[Equation 2] The A _T and F _T values calculated by the above formula (1) or formula (2) calculated by the first calculation means 71 are taken in by the second calculation means 73 connected to the CPU 63, and are as follows. , The load distribution ratio H _i is calculated.

H _i = determined by each load value A _i shown in FIG.
Inclination of each load diagram / A _T , or H _i = B _i / F _T (3) Formula (3) The load distribution ratio obtained by these (3) formulas corresponds to the corresponding bending length ratio. Correspondence has been verified from the results of experiments conducted in advance.

Third computing means 75 connected to the CPU 63
, The current load C ₁ , C ₂ , C ₃ , ..., C _{i of} each intermediate plate 7 from the intermediate plate / load diagram / memory 69, and the second computing means 7.
The load distribution ratio H _{i of the} equation (3) obtained in 3 is taken in, and the target load F _i is calculated as follows.

F _i = F _ci × H _i (4) The target load F _i obtained by the third calculating means 75 and the current load F _ci are corrected by the correcting means 77 connected to the CPU 63 as follows. Correction processing is performed.

ΔF _i = F _i −F _ci (5) Formula: With the correction value ΔF _i obtained by the correction means 77, each intermediate plate adjusting means 28 adjusts each intermediate plate 7, or the main cylinder 15L. , 15R by issuing a position command and crowning cylinder 19 by issuing a pressure command.
The final load distribution ratio of the load distribution ratio H obtained by the correction means
It becomes equal to _i, and each bending angle becomes uniform, so that the bending accuracy can be improved.

Next, the bending operation will be described with reference to the flow chart shown in FIG.
Load detecting means 2 provided on each intermediate plate 7 in step S1
Each load detected in 3 is the intermediate plate / load diagram / memory 69
The intermediate plate / load diagram is stored. From this intermediate plate-load diagram, the maximum values B _i of the slope or plastic range of the elastic region due to the load value A _i is detected.

In step S2 , each intermediate plate 7 is loaded with each load.
When the detection of the inclination or the maximum value B _i by weight value A _i is completed, in step S3, the first calculation means 71,
The above (1) or (2), the sum _{F T} of total _{A T} or maximum value of the gradient is determined. Second in step S4
The calculation means 73 calculates the load distribution ratio H _{i according} to the above equation (3).

In step S5, the target load F _i is calculated by the third calculating means 75 by the above equation (4).
When the calculation of the target load F _i for all the intermediate plates is completed in step S6, the correction means 7 is executed in step S7.
7, the correction value Δ in each intermediate plate 7 is calculated by the above equation (5).
F _i is obtained, and each intermediate plate 7 is adjusted by the intermediate plate adjusting means 28 based on the correction value ΔF _i , or a position command is given to the main cylinders 15L and 15R and a pressure command is given to the crowning cylinder 19. load distribution ratio H _i of the final load distribution ratio of the intermediate plate 7 is determined by the correction means Te
Will be controlled to be equal to.

Therefore, the bending angle of the work with respect to each intermediate plate 7 becomes equal, and the passing bending accuracy can be improved.

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

[0037]

As can be understood from the above description of the embodiments, according to claims 1 and 2, the bending position of the work,
Even if the bending length changes, it is possible to always obtain an appropriate correction amount easily, and obtain a bent product having better bending accuracy than the first workpiece.

[Brief description of drawings]

FIG. 1 shows a main part of the present invention and is a block diagram showing a configuration of a control device.

FIG. 2 is a load diagram of each intermediate plate detected by a load detecting means provided on each intermediate plate.

FIG. 3 is an operation explanatory view for explaining the bending operation of the present invention.

FIG. 4 is a front view of a press brake according to an embodiment of the present invention.

5 is an enlarged cross-sectional view taken along the line VV in FIG.

FIG. 6 is a view taken along line VI-VI in FIG.

[Explanation of symbols]

1 Press brake (folding device) 5 upper table 7 Intermediate plate 9 punch 11 Lower table 13 dies 15L, 15R Main cylinder 19 Crowning cylinder 23 Load detection means 27 NC device (control device) 28 Intermediate plate adjusting means 69 Intermediate plate, load diagram, memory 71 First computing means 73 Second computing means 75 Third computing means 77 Correction means

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Claims (2)

(57) [Claims] 1. A bending method for bending a work by cooperation between a punch provided on an upper table through a plurality of intermediate plates and a die provided on a vertically movable lower table. The load detection means provided on each intermediate plate detects the load value of each intermediate plate during bending, and the load value of each intermediate plate and the punching amount or time of the punch with respect to the die. Obtain the maximum value of the slope or plastic region within the defined range of the elastic region in the diagram and the load distribution ratio of the slope or maximum value, and then calculate the load distribution ratio of each intermediate plate at the target bending angle The bending method is characterized in that the work is bent such that the load distribution ratio is controlled. 2. A bending apparatus for bending a work by cooperation of a punch provided on an upper table through a plurality of intermediate plates and a die provided on a vertically movable lower table. A load detecting means provided on each of the intermediate plates, a position sensor for detecting a moving position of the die with respect to the punch, a load value detected by the load detecting means, and a thrust amount or a thrust detected by the position sensor. A first calculation means for obtaining the maximum value of the inclination of a predetermined range of the elastic region or the plastic region in the load diagram with time;
Second calculating means for obtaining the load distribution ratio of the inclination or the maximum value based on the inclination or the maximum value obtained by the first calculating means, and the load distribution ratio of each intermediate plate at the target bending angle for the second calculating means. A bending apparatus, comprising: a correction unit that corrects the lower table or each intermediate plate so as to control the load distribution ratio of the obtained inclination or maximum value.