JPS58103918A - Method and apparatus for bending of press brake - Google Patents

Abstract

PURPOSE:To improve accuracy of working, to reduce processes of working and to increase efficiency by working after calculating optimum amount of punch driving from working condition and maximum load. CONSTITUTION:Finishing angle, die shoulder width, punch radius, die shoulder radius, thickness of material MP etc. are inputted by an inputting device 18 and stored in a memory 17. The material MP is placed on a die 1B, and the thickness is measured with an ultrasonic thickness meter 14 and stored in the memory 17. Then, a press brake PB controller 13 drives a press brake 12, and performs bending work. When a punch 2 is brought into contact with the material MP, the load applied to the punch 2 is increased and detected by a sensor 11, and processed by an operation processing part 16B, and maximum load is stored in the memory 17. By the above operation, calculation of punch driving considering spring back is performed quickly by an operation processing part 16C and fed back to the PB controller 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides - a press brake bending method for bending a metal plate, particularly a press brake bending a thick steel plate having a thickness of 4.5 [simple] or more; Regarding equipment.

As a conventional bending method, there is a radius bunch air bending method as shown in FIGS. 1 and 2. FIG. 1 is a perspective view showing the overall appearance of the press brake 12, and FIG. 2 shows the state of machining work. In this figure, the universal die 1 that supports the workpiece is comprised of a base IA having a concave portion inside and a die IB held at an appropriate distance from the base IA by a spacer IC. configured, the dice 18
A metal plate (hereinafter simply referred to as "material") MP as a workpiece is placed across between them, and bending is performed by pressing an appropriate punch 2 from above in the figure. 1 With this method, the radius of curvature RP of the tip i of the punch 2 and the shoulder width 2L of the die IB can be easily changed, so it is possible to obtain an arbitrary product radius of curvature with one type of mold. This has the advantage that the mold has high versatility, and that any desired product bending angle can be obtained by changing the amount H of pushing the bunch 2.

A problem with such bending is an elastic recovery phenomenon called springback. This is shown in FIG. In this figure, due to the springback of Δ0 with respect to the material MP, the actual angle is θ,=θ,−Δθ=90°−80 (hereinafter referred to as “finished bending angle”).

This springback amount △- is the bending angle 2 bending radius,
The yield strength varies depending on the plate thickness, and a measurement example is shown in Figure 4. In this figure, the horizontal axis represents the bending radius of the neutral axis in the bending part.

is divided by the plate thickness t, and the springback coefficient Δθ/θ is plotted on the vertical axis.

In addition, as shown in Fig. 2, the above ^ is expressed as 7+r (11) with respect to the curvature r of the bent part.The middle point Q in the figure represents the measured value, and the straight line S
L represents the approximation to point Q, △θ h
...(2) Represented by 0, t. As is clear from this figure, although there is a strong correlation at point Q, no clear relationship can be found, and it can be seen that there is considerable variation.

For this reason, the conventional processing method is to first place the material M on the die IB as shown in Figure 5).
Perform the bending process once as shown in the figure (C), then measure the bending angle θ as shown in the figure (C), and based on this result,
Perform the bending process again as follows. Furthermore, the above-described operations are repeated as necessary to complete the process at a predetermined bending angle θ. In other words, it is not possible to obtain the required bending angle θ in one bending process, and in some cases, two or more processes are required, and if the processing accuracy is increased, production efficiency decreases. Furthermore, there was the inconvenience that the cost had to increase by 15%.

The present invention has been made in view of the drawbacks of the prior art, and provides a press brake bending method and apparatus that can shorten the work process and perform bending with high precision, efficiency, and low cost. Its purpose is to.

That is, the present invention is based on processing conditions predetermined by the die and punch, material conditions measured or determined for each material, the maximum load measured during the bending process of the material, and the finished bending angle. Using a predetermined formula, the optimum spring tension for each material (bunch depth considering the load is quickly calculated during the bending process of the material, and this value is calculated during the process) (
By performing the bending process by feeding back the movement amount of the punch, the work process is shortened, and the work process is made highly accurate, efficient, and low cost. This will be explained in detail by following an example.

FIG. 6 shows a configuration of a press brake bending apparatus according to the present invention, in which a bunch 2 is connected to a press brake 12. The load pressure P exerted by the press brake 12 on the bunch 2 is detected by the load sensor 11, and on the other hand, the operation of the press brake 12 is controlled by a press brake controller (hereinafter simply referred to as "PB controller"). It is now carried out by 13 traps.

Next, as shown in Figure 2, the material M placed on the die IB
An ultrasonic thickness meter 14, which is a means for measuring the thickness t of the material field, is placed at an appropriate position near P.

The outputs of the ultrasonic thickness gauge 14 and the load sensor 11 are subjected to signal adjustment such as υ conversion by the interfaces 15A and 15B, and then processed by an arithmetic processing unit (hereinafter simply K [C
(referred to as PUJ) 16 arithmetic processing units 16A.

16BK is input, and appropriate arithmetic processing is performed here to calculate the plate thickness and load P.

On the other hand, an input device 18 such as a POS keyboard is connected to another arithmetic processing section 16C of the CPU 16, and information necessary for the arithmetic operations to be described later is input. Furthermore, the arithmetic processing units 16A to 16C are all connected to a memory 17, and this memory 17 stores data necessary for arithmetic processing or results of arithmetic processing.

Furthermore, the final processing result is fed back from the arithmetic processing section 16C to the PB controller 13 described above via the interface 15C.

Next, the basic principle of the press brake bending method according to the present invention will be explained.

First, as shown in FIG. 2 or FIG. 3, the die shoulder width 2L, the punch radius RP, and the die shoulder radius RD.

The finished angle θ after the bending process is set appropriately before the bending process.

On the other hand, control the plate width and thickness t of the material MP, and further,
γ, which measures the maximum load Pm during the suppression process of bending the material MP with the punch 2, and the tensile strength a specific to the material MP are expressed as mL, =, yo, -(3+. □ is a constant and varies depending on how the units of other values are determined.

Next, for the material MP having a certain tensile strength, the processing bending angle 01 in consideration of the springback amount Δ0 is expressed as follows. K2 is also a constant. Furthermore, the driving amount H (first
(see figure) is expressed as ...(5).

Therefore, according to Koyu equation (5), the springback amount △θ
By calculating the push-in fH of the punch 2 in consideration of this and performing the bending process based on this calculation, it becomes possible to obtain the originally planned finished angle θ2 after the bending process.

Next, the overall operation of the above embodiment will be explained. In addition, this action! This is shown in the flowchart in Figure 8.

First, the input device 11g inputs the finished angle θ as described above.
1. Die scrap width 2L, punch radius RP, die shoulder radius R
D. Value of board width in material field, etc. (3) to (5) 2C
- Calculation formulas etc. are entered and stored in Memo January 7th.

Next, after the material MP is appropriately placed on the die IB, the plate thickness t is measured using the ultrasonic thickness gauge 14. That is, as described above, after the output of the ultrasonic thickness meter 14 passes through the interface 15A, it is processed by the arithmetic processing section 16A, and the plate thickness t is stored in the memory 17.

After the above operations, the PB controller 13 drives the press brake 12 to perform the bending process. The moving distance of the punch 2 in this operation and the load P applied to the punch 2
Figure 7 shows the relationship between Note that the moving distance of the punch 2 is determined as appropriate for the initial position of the punch 2,
In addition, the applied grape weight P is detected by the load sensor 11. In FIG. 7, before the punch 2 comes into contact with the material MP, the punch 2 only moves with a constant pressure. Next, when the punch 2 comes into contact with the material MP, the resistance force of the material MP acts, so the load P applied to the punch 2 also increases, so that eventually plastic deformation begins and bending is performed. Looking at the transition of the load P during this machining, there is a peak of the load P as shown in the figure, and the load P at this point becomes the maximum load Pm described above. This is detected by the load sensor 11. i.e. load sensor]
After the output of 1 passes through the interface 15B, it is processed by the arithmetic processing unit 16B, and the maximum load Pm is stored in the memory 1.
7 is stored.

Through the above operations, the calculation of the above equation (3) becomes possible,
Furthermore, using equations (4) and (5), it is possible to calculate the punch drive iH considering the springback lid Δθ.
This calculation is quickly performed by the calculation processing section 16C, and the punching amount H is calculated and fed back to the PB controller 13 via the interface 15C. The above calculation is performed in an extremely short time when compared with the movement of the punch 2, so the feedback is performed before the bending angle of the material field reaches the processed bending angle θ. The bending process will be performed by the amount of push-in H.1,
In the embodiments described above, the CPU 16 may be configured with a microcomputer or the like, and the memory 17. One computer system including the input device 18 may be used.

As described above, according to the present invention, the shoulder width of the die.

The optimal punch for the material is determined by processing conditions such as the radius of the hole, punch radius, finishing angle θ, material conditions such as the width and thickness of the workpiece material, and the maximum load during the bending process. Since the amount of additional work is calculated and the bending process is performed based on the calculated amount, the processing accuracy can be improved. , a load measuring means for measuring the maximum load, an arithmetic processing unit that calculates the optimum punch depth for the material from the detection results of these means, and control of the movement of the punch based on the punch depth calculated by this. Since the bending process is performed using a press brake bending apparatus equipped with a press brake controller, the bending process can be performed efficiently and at low cost by shortening the work process, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing the overall appearance of the press brake, Fig. 2 is an explanatory view showing one mode of bending by the press brake, Fig. 3 is an explanatory view showing the state of springback, and Fig. 4 is an explanatory view showing the state of springback. The figure is a graph showing the variation in the amount of springback due to bending pressure, Figure 5) to Φ) are explanatory diagrams showing an example of the conventional bending process, and Figure 6 is a graph showing the bending process of a press brake according to the present invention. FIG. 7 is a circuit block diagram showing an example of a configuration, FIG. 7 is a line diagram showing an example of detection by a load sensor, and FIG. 8 is a flowchart showing an outline of the operation of the device shown in FIG. 6. 1B... Dice, 2... Punch, 11... Load sensor, 12... Press brake, 13... Press brake controller, 14... Ultrasonic thickness gauge, 16...
...Arithmetic processing unit, 17...Memory, MP--Material, H゛°゛Punch depth, 2L...Dice shoulder width, P...
... Load, Pm ... Maximum load, RP ... Punch radius, RD ... Die shoulder radius, θ, ... Finished bending angle, △θ ... Springback t, t ... Material Thickness, b...Width of the material. Figure 4 (A) (B) (C) (
Dl Procedural amendment July 23, 1980 Commissioner of the Japan Patent Office 1, Indication of the case Patent Application No. 204177 of 1983 3, Person making the amendment Relationship to the case Patent applicant (123) Komatsu Ltd. 4, Agent (6th floor, Ginza Daisaku Building, 2-11-2 Ginza, Chuo-ku, Tokyo 104) Tel: 03-545-3508 (Representative) 5
, "Oblique perspective view" in the second line of page 3 of the specification to be corrected is corrected to "perspective view."

Claims (1)

[Claims] (11) In a press brake bending method for bending a material using a die and a punch, processing conditions determined by the die and punch, material conditions measured for each material, Based on the maximum load measured during the bending process of the material and the finished bending angle, calculate the punch depth for each material, taking into account the springback amount of the material, and calculate this punch depth. (2) In a press brake bending device equipped with a die and a punch, the material before processing is placed on the die. means for measuring the thickness of the punch, means for measuring the load applied to the punch by a press brake during the bending process, and material conditions determined by the processing conditions determined by the die and punch, the finished bending angle, and the material. and a memory storing an arithmetic formula for calculating the amount of punching of the punch in consideration of the amount of springback, and calculating the amount of punching for each material from the stored contents of this memory and the measurement results of both the measuring means. What is claimed is: 1. A press brake bending device comprising: a calculation processing unit that performs the bending process, and a press brake controller that controls the movement of the punch during the bending process in accordance with the calculated punch drive amount.