JPS6245425A - Control method for bending machine - Google Patents

Abstract

PURPOSE:To increase the product accuracy by performing the deflection calculation of a frame and by operating the optimum attitude of the frame as well, then by bending a sheet material based on the arithmetic result thereof. CONSTITUTION:The control module RCM of a movable frame 7 and NC and NC are provided inside a control panel 19. Moreover a linear scale 25 is fitted around the both ends of the movable frame 7 and a detecting head 27 is arranged on the fitting panel 27 of the lower part frame 3 as well. The correction value of the frame intervals at the right end and left end of the movable frame 7 is operated by calculating the deflection of the upper and lower frames for the working conditions of the width (l), thickness (t), etc. of a sheet material W with the module RCM. With this method the upper and lower frames are controlled in the optimum attitude, then the bending is performed at the prescribed angle. The product accuracy is increased due to the both ends being bent at the same angle irrespective of the bending width taking into consideration the frame deflection.

Description

[Detailed description of the invention] [Industrial application field] This invention→→ relates to a method of controlling a folding machine.

[Description of Prior Art] Generally, in a bending machine, the upper and lower frames to which the upper and lower molds are attached are adjusted at a constant interval, and one of the upper and lower frames is made movable to control the positioning at this adjusted interval. A prescribed bending process is being performed.

However, it is known that the frame of a bending machine is bent depending on its rigidity. For example, when driving and controlling both ends of a movable frame using two cylinder devices, the maximum deflection occurs at the central position.

Therefore, when using such a bending machine to perform so-called single-load bending, even if both ends of the frame are controlled at a constant interval, the frame will experience maximum deflection near the center. There is a problem in that the bent cubes at the ends near the center position become loose, resulting in poor quality of the product.

[Object of the Invention] The object of the present invention is to provide a method for controlling a bending machine that can improve the above-mentioned problems and improve product accuracy even under a single load.-0 [Summary of the Invention] The above-mentioned In order to achieve the object, the method of the present invention calculates the deflection of the frame in advance based on processing conditions such as the bending width of the machine to be processed, the plate thickness, the bending position, and the rigidity of the mold mounting frame. The proper posture of the frame is calculated so that both ends of the plate material are bent at a predetermined angle, and the plate material is bent at a predetermined angle by controlling the frame to the calculated posture.

[Description of Embodiments] Figures 1 to 3 are diagrams showing an example of a folding machine in which the present invention can be carried out. Figure 1 is a side view of the folding machine, and Figure 2 is a side view of the folding machine. The plan view and FIG. 3 are block diagrams of the air circuit for controlling the IiT rib free frame.

As shown in FIGS. 1 and 2, the folding machine 1 has a lower frame 3, a side frame 5 (5Δ, 5B), and a movable frame 7 that can be raised and lowered. This bending machine 1 is of a type that bends a plate material W of a predetermined width between a die attached to the upper end of a lower frame 3 and a bunch 11 attached to the lower end of a movable frame 7.

The movable frame 7 is connected to the side frame 5 (5Δ, 5b
) mounted above the cylinder 13 (13Δ, 13B
> Piston and piston rod 15 (1
5A, 15B). The connection between the movable frame 7 and the pistons 1 (15△, 15B) is supported so that they can swing freely within the plane shown in FIG.
Servo valves 17 (17A, 17B>) are attached to the upper end of B).

A control panel 19 is provided on one side of the bending machine 1, and this control panel includes an NG device NC for controlling the bending machine 1 and a movable frame control module RC for controlling the movable frame. ) M is already stored. A pendant 21 provided on the upper front side of the bending machine 1 is attached to the control panel 19.
It is connected via the turning duct 23 and controlled! The pendant 21 is configured to be able to rotate around one plate and to be rotatably connected to the attachment point of the turning duct 23, and is configured to be movable in the left and right directions on the front surface of the bending machine 1.

An operation panel (not shown) equipped with switches and the like for operating the folding machine 1 is attached to the front surface of the pendant 21.

A linear scale 25 (25Δ, 25B) is attached near both ends of the movable frame 7 of the bending machine 1, and facing the linear scale 25 (25A, 25B),
The detection head 27 (27A, 27B) is attached to the lower frame 3.
It is attached to a fixed mounting plate 29 <29A, 29B>. This linear scale 25 (25△,
25B> and the detection head 27 (27A, 27B), the detection accuracy of the position detection device is 0.01 mm-0,
It is said to be about 0.001mm.

Note that the bending machine 1 is attached with a foot beta FS, and the foot beta FS has a foot beta D for descending commands.
S and a foot beta US for ram raising command. The operator can command the movable frame 7 to move upward or downward by stepping on the footplate FS.

The cylinders 13<13A+13B> are supplied with oil at a predetermined pressure from a hydraulic circuit (not shown), and are connected to the servo valve 1.
7 (17A, 17B) performs aperture control to control the movable frame 7 to a predetermined position in a predetermined direction at a predetermined speed.

As shown in FIG. 3, the movable frame control module R
The OM includes a command section 31, a drive control section 33, two servo amplifiers 35 (35A, 35B>) and two frequency-voltage converters 37 (37A, 37B).

The command section 31 has a condition setting section 31a, a calculation section 31b, and a command value output section 31e.The condition setting section 31a sets machining conditions, and the calculation section 31b performs predetermined processing based on these conditions. It performs calculations and outputs a predetermined command signal from the command value output section 31c.

The conditions in the condition setting section 31a are set based on processing data or operation of a keyboard (not shown), and the contents of the conditions are the width and thickness of the plate material W in this example. This is because, in this example, the width α is
This is because the position of the plate material W is set so as to speak on the left side, and also because the rigidity of the frame 5.7 is initially set.

In general, in addition to the width and thickness of the plate material, the configuration of the frame 5.7 and the setting position of the plate material W should also be considered as conditions.

The processing contents of the calculation section 31b are shown in a flowchart in FIG.

Step 401 shows the above-mentioned condition setting process.

Step 403 is to judge whether or not single load control will be performed from now on. If single load control is performed, step 405
Move to.

Then, in step 405, the bending load is calculated according to the plate thickness [, and then in step 407, the deflection δ1 of the upper and lower frames at the inner end position of the plate material W shown in FIG. δ2
Calculate.

If the movable frame 7 is controlled so that the distances a and b between the left and right frames 5 and 7 are the same in FIG. 2, the deflections δ1 and 62 will be as shown in FIG. It becomes like this.

As shown in FIG. 5, at the right end position of the plate W, the upper and lower frames are bent δ1. δ1 for the left end based on δ2
This means that a deflection of +62 has occurred. This is the reason why conventionally, the bending angle of the portion closer to the center of the frame is weaker.

Therefore, in step 409, a correction value χ is calculated to correct the right-end frame interval in FIG.

If the frame length is L, the correction value χ should be δ1 → ~ δ2
) / Becomes love.

Step 411 uses this correction value χ to calculate right positioning data b=a−χ.

Therefore, the control position of the movable frame of the correction value is as shown in FIG. That is, the frame interval d at the right end of the plate material W of the width bar is exactly the same as a at the right end.

In FIG. 3, the command value output unit 31c adjusts the left end of the movable frame 7 by 23 points based on the result calculated in this way.
A command signal is output to position the right end at point 25 (see FIG. 6).

The drive control unit 33 controls the movable frame 7 based on the command from the command unit 31 and the feedback signals from the detection heads 27A and 27B.
A predetermined voltage V is output to each of the servo amplifiers 35A and 35B until the left and right end portions reach the P3.25 point. Servo amplifier 35A.

37B controls the movable frame 7 to a predetermined speed while obtaining a speed feedback signal.

As a result of the above, the movable frame 7 is controlled to a predetermined position in the attitude shown in FIG. 6, and both ends of the plate material W of the width bar shown in FIG. 2 are bent at a predetermined angle.

In addition, in the above embodiment, as shown in FIG. 2, the plate material W is aligned to the left, but this is the same even if it is aligned to the right. The same effect can be applied even when the plate material W is positioned at an intermediate position within the frame length by changing the calculation formula.

[Effects of the Invention] As described above, in the method of this invention, the frame spacing at both ends of the plate can be controlled to be the same in consideration of frame deflection, so both ends can be bent at the same angle regardless of the bending width. This makes it possible to improve product accuracy even with a single load.

[Brief explanation of drawings]

Figures 1 to 3 show an example of a folding machine that can carry out the method of this invention, with Figure 1 being a side view of the folding machine, Figure 2 being a front view thereof, and Figure 3 being a side view of the folding machine. is a block diagram of a control circuit of a servo valve. FIG. 4 is a flowchart showing an example of processing by the arithmetic unit, and FIGS. 5 and 6 are explanatory diagrams of the operation of the embodiment of the method of this invention. 1...Bending machine 31a...Condition setting section 31b...Calculating section δ1. δ2...Deflection W of the upper and lower frames...Control position L of the movable frames P3 and P5...Frame length A...Width of the plate material

Claims (1)

[Claims] The deflection of the frame is calculated in advance based on the processing conditions such as the bending width, plate thickness, bending position, and rigidity of the mold mounting frame of the plate material to be processed, and based on this deflection, both ends of the plate material of a predetermined width are A method for controlling a bending machine, comprising: calculating an appropriate posture of the frame so that the plate can be bent at a predetermined angle, and controlling the frame to the calculated posture to bend the plate material at a predetermined angle.