JPH04135019A - Method and device for bending metallic sheet - Google Patents

Abstract

PURPOSE:To make it possible to smoothly position by releasing clamp of the metallic sheet material, at same time, applying the magnetic attracting force at the top end of the metallic sheet, attracting the top end surface of the metallic sheet to the abutting surface of the back gage and positioning it on the position of the upper die being approached near to the metallic sheet. CONSTITUTION:Just before the top end of the metallic sheet 11 is abutted on the abutting surface 33 of the back gage 31, the feeding motion for the metallic sheet is stopped, the contact of the metallic sheet to the abutting surface is realized with the magnetic attracting force of the permanent magnet 34. The complicated torque controlling is unnecessary, the metallic material feeding operation is realized with a robot. Because the metallic sheet is restricted to move upward and downward between the upper die 6 and the lower die 4 during magnetic attracting time, the metallic sheet material is deformed smoothly to the abutting surface while keeping its horizontal posture. Therefore, without requiring the complicate torque control, the operation for feeding the metallic sheet can be realized with the robot, the labor saving and the smooth positioning can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a bending method for bending a metal plate material and a bending device for carrying out the bending method.

<Prior Art> For example, when bending a metal plate using a press brake, one worker is assigned to each machine to perform the bending process.

First, the worker grasps the base end of the metal plate, feeds the tip between the upper die and the lower die, brings the end face into contact with the abutment surface of the back gauge, and then operates the die device to release the metal plate. Performing bending work.

However, in this bending method, the metal plate must be grasped and fed, resulting in a heavy workload.In recent years, it has been proposed to have a robot carry out this feeding work in order to save labor.

<Problems to be Solved by the Invention> When this type of feeding work is replaced by robots, in addition to the operation of feeding the metal plate between the upper mold and the lower mold, It is necessary to press it against the abutment surface of the back gauge with appropriate pressure. However, in order to properly control this type of pushing operation, precise torque control of at least two axes is required, but this type of control is technically extremely difficult, and in reality, this hinders labor-saving by robots. This is a factor.

The present invention was made in view of the above-mentioned problems, and includes a method for bending a metal plate that automates the feeding operation of the metal material and achieves smooth bending without requiring complicated torque control. The purpose is to provide equipment.

<Means for Solving the Problems> The method for bending a metal plate according to the present invention is characterized by carrying out the following steps in series.

First, in the first process, the metal plate is gripped and fed between the upper die and the lower die, and when the tip of the metal plate reaches a position in front of the abutment surface of the bank gauge, the feeding operation is stopped and the metal plate is placed on the lower die. to support the metal plate. In the next step, the upper mold is lowered toward the metal plate, and the lowering operation is stopped at a position where the upper mold approaches the metal plate to form a restrained state of the metal plate. In the following process, the grip on the metal plate is released, and a magnetic attraction force is applied to the tip of the metal plate to attract and position the tip of the metal plate to the abutment surface of the back gauge. Finally, the metal plate material is bent between the upper mold and the lower mold.

Further, the metal sheet bending apparatus according to the present invention includes a mold device, a bag gauge, a control device, and a material feeding mechanism.

The mold device includes an upper mold and a lower mold that are vertically opposed to each other, and an elevating mechanism that moves the upper mold up and down. The back gauge is arranged at the rear of the mold device, and has a permanent magnet or an electromagnet built into its abutment surface. The control device can position the upper mold relative to the lower mold by controlling the lifting and lowering operation of the lifting mechanism. The material feeding mechanism has a hand portion that grips a metal plate, and feeds the hand portion until the tip of the metal plate reaches a position in front of the abutment surface of the back gauge.

Function> The feeding operation of the metal plate is stopped just before the tip of the metal plate hits the abutment surface of the back gauge, and the contact of the metal plate with the abutment surface is achieved by magnetic attraction, so complex torque is not required. Robots can perform the work of feeding metal materials without the need for control. Furthermore, during magnetic attraction, the vertical movement of the metal plate material is restricted between the upper mold and the lower mold, so that the metal plate material can be smoothly displaced to the abutment surface while maintaining its horizontal position.

<Example> FIG. 1 shows a press brake for carrying out the bending method of the present invention.

In the illustrated press brake, a machine body 1 and a robot 2 are installed on the floor, and a control box 14 is integrally attached to the side surface of the machine body 1.

A table 7 for installing a lower mold 4 is attached to the front bed 3 of the machine body 1, and a ram 8 is disposed between the left and right side frames 5.5 so as to be movable up and down, facing the table 7. ing.

As shown in FIG. 2, an adapter 9 is provided at the lower edge of the ram 8, and the upper die 6 is set at the lower end of the adapter 9 via a holder IO.

A lifting mechanism 13 whose driving source is an AC servo motor 12 is connected to the ram 8 .

This elevating mechanism 13 is for reciprocating elevating and lowering the ram 8 along guides (not shown) provided on both sides of the side frame 5.5. A feed screw shaft 15 is connected via a power transmission mechanism 17, and the feed screw shaft 15 is integrated with the ram 8 or screwed into a nut 16. The feed screw shaft 15 is rotatably supported by a bearing 18, and the feed screw shaft 15 rotates in forward and reverse directions as driven by the AC servo motor 12, and the ram 8 moves up and down in a reciprocating manner according to the direction of rotation.

The control box 14 has a key operation section and a CRT display section on the front, and the lifting mechanism 1 is installed inside the box.
A control device 21 (shown in FIG. 3) is incorporated therein to control the operations of 3.

FIG. 3 shows an example of the circuit configuration of the control device 21 built into the control box 14. As shown in FIG.

In the figure, CP (J (Central Process
ing Unit) 22 is ROM (Read 0nl
y Memory) 23 and RAM (Random A
It constitutes a microcomputer together with the access memory (access memory) 24, and executes instruction analysis and various calculations. The ROM 23 stores programs for machine control, etc., and the RAM 24 stores calculation results, other data, and user programs. Note that the key operation section 19 is for performing machine operations and data input, and the CRT display section 20
is used to display input/output data, etc.

Further, the CPU 22 provides the output to the AC servo motor 12 to the servo amplifier 25, and the servo amplifier 25 amplifies this and provides it to the AC servo motor 12. This AC servo motor 12 is equipped with an absolute rotary encoder 26.
and a torque detector 27 are connected. The encoder 26 detects the rotation angle of the AC servo motor 12, that is, the current moving position of the ram 8 (upper die 6), and transmits the value to the CPU.
Output to 22. Further, the torque detector 27 monitors the motor current and detects the torque of the AC servo motor 12. Note that the electromagnet 28 is used in place of the permanent magnet 34 described later.

The robot 2 moves a magnetic metal plate material 1 to be processed.
In FIG. 1, 29 is a multi-jointed robot arm, and the tip of this robot arm 29 grips the metal plate 11. It is equipped with a hand section 30 for use.

A back gauge 31 is disposed at the rear of the table 7, as shown in FIGS. 4 and 5.

The back gauge 31 is for positioning the metal plate material 11, and has a pair of left and right abutment members 32, 32 arranged so as to be movable and adjustable in the front-rear direction and the up-down direction. The front surface of each abutment member 32 is a vertical and flat abutment surface 33
A plurality of permanent magnets 34 are embedded inside each abutment member 32, and each magnetic pole is aligned with the abutment surface 33.
It is exposed to. As will be described later, this permanent magnet 34 is for magnetically adsorbing the tip end surface of the metal plate material 11.
Of course, it is also possible to replace this permanent magnet 34 with an electromagnet.

FIG. 7 shows a control procedure for the machine body 1 and the robot 2 for carrying out the bending method of the present invention.

First, in step 1 of the figure (indicated by rsTIJ in the figure), when it is confirmed that the ram 8 is waiting at the upper limit position and the positioning of the back gauge 31 has been completed, the CPU 22 of the control device 21 is set up in step 2. A pointing instruction signal is generated and sent to the robot 2. This setting instruction signal is a signal for requesting positioning of the metal plate material 11, and when the robot 2 receives this setting instruction signal, the determination in step 1' becomes "YES", and the next step 2', 3', the hand part 30 is a metal plate material 11
, and move the metal plate LL into the upper die 6 and the lower die 4.
Send it between. As a result, when the hand part 30 moves forward by a predetermined stroke and the tip of the metal plate L1 reaches a position in front of the abutment surface 330 of the back gauge 31, the feeding operation is stopped and the metal plate IL remains on the lower mold 4. (step 4'5'). At this time, the gap a between the tip of the metal plate material 11 and the abutting surface 33 is
0 releases the metal plate 11, the magnetic attraction force of the permanent magnet 34 acts to perform the adsorption operation, so this value is set to an appropriate value, but this value must be set strictly as it allows a considerable error range. No precise position control is required. Furthermore, in this embodiment, the stopping operation is realized at a position in front of the forward distance of the hand part 30 by the distance a, but the stopping position is not limited to this, and the stopping position may also be controlled using an optical sensor, a proximity switch, etc. Of course it is possible.

Once the metal plate material 11 is set in this way, step 6'
Then, the robot 2 sends a set completion signal to the machine body 1. When the CPU 22 of the control device 2I accepts this, step 3 becomes "YES" and the lifting mechanism 13 is activated.
The ram 8 moves downward toward the metal plate 11 (step 4).

When the upper mold 6 has descended to a predetermined position close to the upper surface of the metal plate 11 as shown in FIG. 6, the CPU 22 stops the lowering operation of the ram 8 (step 6). At this time, the gap between the lower end of the upper die 6 and the upper surface of the metal plate material 11 is as follows:
This is set in consideration of the error in the thickness of the metal plate 11, and by stopping the upper mold 6 close to the metal plate 11, the metal plate 11 is held in a restrained state. Even if the grip on the metal plate 11 is released in the process, the horizontal attitude of the metal plate 11 is maintained.

When the downward movement of ram 8 stops, in the next step 7, C
The PU 22 generates a preparation completion signal and sends it to the robot 2. When robot 2 receives this signal, step 7'
The determination is “YES”, and the robot 2 moves the hand part 30
is released to release the grip on the metal plate 11 (stencil 18'). As a result, the metal plate material 11 is connected to the hack gauge 31.
It is attracted to the abutting surface 33 by the magnetic attraction force of the permanent magnet 34 embedded in each of the abutting members 32, 32, and is thereby positioned. During this suction operation, the vertical movement of the metal plate 11 is restricted between the upper die 6 and the lower die 4, so the metal plate 11 is smoothly displaced to the abutment surface 33 while maintaining its horizontal position. . When the metal plate material 11 is released,
The robot 2 generates a release signal and sends it to the machine body 1, and then moves the hand section 30 backward (steps 9' and 1).
0'). When this release signal is received by the machine body 1, the machine body 1 executes the bending process of the metal plate material 11 between the upper die 6 and the lower die 4.

Note that when an electromagnet is used in place of the permanent magnet 34, when the control device 21 of the machine body 1 receives the release signal,
The electromagnet 28 is energized and energized to attract the metal plate 11 (steps 8 and 9).

<Effects of the Invention> As described above, the present invention grips a metal plate and feeds it between the upper die and the lower die, and when the tip of the metal plate reaches a position in front of the abutment surface of the back gauge, the feeding operation is performed. Then, the upper mold is lowered and the lowering operation is stopped when the upper mold approaches the metal plate to form a restrained state of the metal plate, and then the grip on the metal plate is released and the back gauge is released. Because the tip of the metal plate is magnetically attracted to the abutment surface for positioning, there is no need for complicated torque control as in conventional methods.
The work of feeding metal plates can be accomplished by robots, which can save labor. Moreover, during magnetic adsorption, the vertical movement of the metal plate is restricted between the upper and lower molds, so the metal plate is displaced toward the abutment surface while maintaining its horizontal position.
Smooth positioning is possible.

[Brief explanation of the drawing]

FIG. 1 is a side view of the press brake according to the present invention, FIG. 2 is a sectional view showing an example of the configuration of the upper and lower molds and the lifting mechanism, FIG. 3 is a block diagram showing an example of the circuit configuration of the control device, and FIG. FIG. 5 is a plan view of FIG. 4, FIG. 6 is a side view showing the restrained state of the metal plate, and FIG. 7 is a bending process according to the present invention. 2 is a flowchart showing a control procedure for a machine body and a robot for carrying out the method. 1...Machine body 2...Robot 4...
...Lower die 6...Upper die 11...Metal plate material 13...Elevating mechanism 21...Control device 31...Back gauge 32...Abutting member 33... Abutment surface 34...Permanent magnet

Claims (1)

[Claims] [1] Grip a metal plate and feed it between the upper die and the lower die, and stop the feeding operation when the tip of the metal plate reaches a position in front of the abutment surface of the back gauge. a step of lowering the upper mold toward the metal plate and stopping the lowering operation at a position where the upper mold approaches the metal plate to form a restrained state of the metal plate; , while releasing the grip on the metal plate,
A process of applying a magnetic attraction force to the tip of the metal plate to attract and position the tip of the metal plate to the abutment surface of the back gauge, and a process of bending the metal plate between the upper die and the lower die. 1. A method for bending a metal plate, characterized by carrying out a series of steps. [2] A metal plate bending device having a mold device, a bag gauge, a control device, and a material feeding mechanism, the mold device having an upper mold and a lower mold located vertically opposite each other;
a lifting mechanism that moves the upper mold up and down, the back gauge is arranged at the rear of the mold device, and a permanent magnet or an electromagnet is incorporated in the abutment surface, and the control device controls the lifting and lowering movement of the lifting mechanism. The material feeding mechanism has a hand portion that grips the metal plate until the tip of the metal plate reaches a position in front of the abutment surface of the back gauge. A metal plate bending device into which the hand portion is sent.