JPH0818069B2 - Press brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a press brake capable of driving a mold by position control or pressurizing force control.

(Prior Art) As is well known, the bending method in a press brake is
It can be roughly classified into three types shown in FIGS.

The partial bending shown in FIG. 4 is a method in which the punch 3 is controlled to a predetermined position with respect to the die 1 so that the plate material W is bent without being brought into close contact with the V groove of the die 1.

In the bottoming shown in FIG. 5, the work W is moved to the V of the die 1 by pressing the punch 3 against the die 1 with a predetermined pressure.
The groove is bent at a predetermined angle.

In the coining shown in FIG. 6, the pressing force of the punch 3 is made about 5 times higher than that of the bottoming shown in FIG.
The work W is bent into a predetermined shape with the V groove.

On the other hand, examples of conventional press brakes include those in which the die is driven by a servomotor and those in which the die is driven by a hydraulic cylinder.

The former is suitable for performing the partial bending because the mold can be controlled to a predetermined position.

The latter is suitable for performing the bottoming or coining because the die can be controlled with a predetermined pressing force.

(Problems to be Solved by the Invention) However, as described above, the conventional press brakes are roughly classified into those capable of position control and those capable of pressurizing force control. There was a problem that it was difficult to do.

However, there is an example in which the mold can be driven by a hydraulic servo motor to implement the full bending method. However, since this uses a hydraulic servo, the device becomes large and its control is difficult. There was a point.

Therefore, an object of the present invention is to provide a press brake having a simple structure and capable of easily performing various bending such as partial bending, bottoming, and coining.

[Structure of the Invention] (Outline of the Invention) A press brake according to the present invention for solving the above-mentioned problems is provided with a motor for driving a mold, and a position detector for detecting a driving amount of the motor and an output torque of the motor are provided. A torque detector for detection is provided, data input means for inputting bending data, and position control means for controlling the mold to a predetermined position by servo-controlling the motor based on a position command and a feedback signal of the current position. And torque control means for controlling the pressure of the mold to a predetermined one by controlling the torque of the motor based on the torque command and the feedback signal of the current torque, and switching between the position control means and the torque control means. It is characterized in that the motor is driven by position control or torque control by a control device provided with control switching means.

(Embodiment) FIG. 1 is a side view of a press brake according to an embodiment of the present invention, FIG. 2 is a block diagram of a control device, and FIG. 3 is a timing chart showing a control example.

As shown in FIG. 1, the press brake of this example has a fixed table 5 on which a die 1 and a punch 3 are mounted and a ram 7, which includes a decelerator 9, a ball screw 11, and a pressure detector. A motor M with an encoder E and a tachogenerator TG is driven up and down via 13.

As shown in FIG. 2, the control device 15 includes a data input display unit 17, and connects the position control unit 21 and the torque control unit 23 connected to the main CPU unit 19 to the servo amplifier 27 via the control switching unit 25. By doing so, the motor M is driven by position control or torque control. The pressing force detected by the pressing force detector 13 is converted into the torque value of the motor M, and the torque control unit 23
Used in.

 Next, a control example will be shown.

At the start of bending at time t _{1 in} FIG. 3 (a), the punch 3 descends at high speed and approaches the plate material W and the die 1. This control is performed by the positioning control unit 21.

Then, upon reaching the commanded position by the main CPU unit 19 changes the speed to a low speed at time t ₃ ~t _4, further lowering the punch 3. When the punch 3 sandwiches the plate material W with the die 1 and reaches the position of the bottoming or just before that, time t ₆
Switch to torque control with.

Therefore, from time t _{6 to} t ₇ , the bending pressure is maintained by torque control.

After that, the main CPU unit 19 again outputs a command to the control switching unit 25, switches the torque control to the positioning control, and raises the punch 3 at high speed. FIG. 3 (b) shows the torque generation status between the control pressures.

Thus, in this example, position control or torque control,
Alternatively, since control in which torque control is added to position control can be freely selected, various bending methods can be carried out in a mode in which stable bending accuracy is obtained.

Further, since the actual torque value is detected, unnecessary torque is not generated, which is energy-saving and does not cause mold damage or machine damage accident.

Furthermore, since the motor M is driven by the position control unit 21 or the torque control unit 23, the device configuration is simple and the control process is easy.

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

[Advantages of the Invention] As described above, the present invention is a press brake that drives a mold with a motor capable of position control or torque control.
Easy to configure, partial bending, bottoming,
Various bending such as coining can be done easily.

[Brief description of drawings]

FIG. 1 is a side view of a press brake according to an embodiment of the present invention, FIG. 2 is a block diagram of its control device, FIG. 3 is an explanatory view of a control example, FIG. 4 is an explanatory view of partial bending, and FIG. FIG. 5 is an illustration of bottoming, and FIG. 6 is an illustration of coining. 1 ... Die, 3 ... Punch, 1 ... Pressurization force detector W7 ... Data input display device 19 ... Main CPU unit 21 ... Position control unit 23 ... Torque control unit 25 ... Control switching unit 27 ... … Servo amplifier M… Motor

Claims (1)

[Claims] 1. A motor for driving a die, a position detector for detecting a driving amount of the motor and a torque detector for detecting an output torque of the motor, and a data input means for inputting bending data. , Position control means for controlling the mold to a predetermined position by servo-controlling the motor based on the position command and the feedback signal of the current position, and torque control of the motor based on the torque command and the feedback signal of the current torque Position control or torque control of the motor by a control device having a torque control means for controlling the pressing force of the mold to a predetermined one and a control switching means for switching the position control means and the torque control means. A press brake characterized by being driven by.