JP3183420B2 - Press brake processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a press brake in which the speed of a ram can be varied.

[0002]

2. Description of the Related Art Conventionally , there is a press brake for bending a plate-shaped work in which a ball screw is rotated by a servomotor to vertically move a ram screwed to the ball screw (for example, JP-A-63-
No. 290623).

[0003]

However , in the above-mentioned conventional press brake, since the servomotor and the ball screw are connected via a speed reduction means having a constant reduction ratio, for example, the bending capacity is increased. As a result, the speed of the ram is reduced to lower the productivity, and conversely, when the productivity is to be increased, the bending capacity is reduced. The present invention has been made to improve the above disadvantages.
An object of the present invention is to provide a press brake processing method capable of improving productivity without lowering bending ability.

[0004]

According to the present invention, in order to achieve the above object, the rotation of a servo motor is controlled by a ball screw.
The ram 5 is moved up and down by the up and down drive mechanism 4 composed of the window 12.
And the upper mold 18 attached to the ram 5 and the press
Between the lower mold 19 fixed on the table of the main body.
Of the press brake which is designed to bend the
In the processing method, the ram 5 is lowered at a high speed,
The upper die 18 attached to the workpiece 5 approaches the work 20.
A first step, in which the upper die 18 contacts the work 20 and the lower die
When the bending of the work 20 is started between
Of the transmission torque of the motor 14 for driving the motor 5
The load is taken in by the container 25 and converted into a pressurized load, and a predetermined bending load
The pressure load is larger than the predetermined bending load.
If it is difficult, it is determined that the bending process is a thick plate, and the motor 14
The speed is reduced by a speed reducer 16 provided between the vertical drive mechanism 4.
As a result, the transmission of the motor 14 is switched to low speed and high torque.
Replacement process for bending workpieces with large bending capacity
And the pressure load is smaller than the predetermined bending load.
Is determined to be bending of a thin plate, and the speed is reduced by the speed reducer 16.
Without selecting and performing the bending of the work as it is a high speed
And a second step that is performed selectively and automatically.
Press brake processing method .

[0005]

[Operation] By the above processing method , a thin plate with a small bending load can be bent at a high speed, and a thick plate with a large bending load can be bent down by lowering the ram at a low speed only during bending, so that the bending capacity can be maintained without reducing productivity. Can be increased.

[0006]

[Embodiment] A press breaker according to an embodiment of the present invention.
The processing method of the key will be described in detail with reference to the drawings. FIG. 1 is a front view of a press brake, and FIG. 2 is a side view thereof . In these figures, 1 indicates a press body, 2 indicates an operation panel, and 3 indicates a back stop. The press body 1 has a structure in which box-shaped side frames 1b are arranged at both ends of a bed 1a. A ram 5 which is moved up and down by a vertical drive mechanism 4 installed below the side frame 1b is provided above the bed 1a. Is provided.

[0007] Both ends of the ram 5 are side frames 1b.
The upper part of a bracket 6 provided in the side frame 1 b is fixed to both ends of the ram 5. As shown in FIGS. 2 and 3, the bracket 6 is formed in a substantially U-shape whose lower side is open, and has an upper side 6a.
Are fixed to the front and rear surfaces of the ram 5 by fixing members 7, and the lower end portion is fixed to the upper surface of the guide member 8 by fixing members 9. The guide member 8 also has a substantially U-shape whose lower side is open, and both side portions 8a are supported by guide posts 10 arranged in front and rear of the press body 1 so as to be vertically movable as shown in FIG. .

A nut 13 screwed to the ball screw 12 of the vertical drive mechanism 4 is fixed to the upper side 8b of the guide member 8. The vertical drive mechanism 4 is installed in the lower part of each side frame 1b, and has the ball screw 12 supported in the side frame 1b by a bearing 11. The lower end of the ball screw 12 is interlocked by an output shaft 16a of a speed reducer 16 that reduces the rotation of a servomotor 14 installed behind the side frame 1b to a plurality of stages, for example, two stages, and a power transmission means 15 such as a timing belt. The left and right ball screws 12 are rotated synchronously by the servo motor 14. The speed reducer 16 includes a high speed gear 16c and a low speed gear 16c in a gear case 16b as shown in FIG.
d are provided, and these high and low speed gears 16c, 16d
Is selected by the high-speed clutch 16e and the low-speed clutch 16f, so that the rotation input to the input shaft 16g from the servomotor 14 can be shifted to two stages and output from the output shaft 16a.

On the other hand , an upper die 18 is attached to a lower portion of the ram 5, and a plate-like member is provided between the upper die 18 and a lower die 19 fixed on a table 1c provided on an upper portion of the bed 1a. Work 20 can be bent.
In the figure , reference numeral 21 denotes a position detector, which has an absolute encoder 23 connected to an endless timing belt 22. The position detectors 21 are provided at both ends of the ram 5, and both ends of the ram 5 are connected to the timing belt 22 via pickups 24 fixed to the ram 5. By rotating the timing belt 23, the positions of both ends of the ram 5 are detected by the absolute encoder 23.

[0010] Then, the position data of the ram 5 at both ends, which are detected by these position detector 21 is input to the controller 26 for controlling the vertical movement of the ram 5. The control device 2
6 is connected to the servo motor 12 via the servo amplifier 27 as shown in FIG. 6, and is connected to the servo motor 14 based on signals input from the position detector 21 and the torque detector 25.
The high and low speed clutches 16e and 16f of the speed reducer 16 are controlled as follows.

Next, the operation will be described with reference to a flowchart shown in FIG. 7. In bending the work 20, first, data necessary for bending is input from the operation panel 2 and the work is started. In step (1), the low speed clutch 16f of the speed reducer 16 is turned on, and in step (2), the high speed clutch 16e is turned on. In this state, step (3)
When the servo motor 14 starts rotating, the rotation of the servo motor 14 is changed to the output shaft 16a via the high-speed gear 16c.
Therefore, the ball screw 12 is rotated at high speed via the power transmission means 15.

[0012] Thus, the ram 5 which has been stopped at the top dead center is lowered at a high speed as shown in Figure 8, the upper die 18 mounted to the ram 5 approaches the workpiece 20 (Step 4). Then , the upper mold 18 contacts the work 20 and the lower mold 19
When the bending of the work 20 is started between the high-speed clutch 1 and the high-speed clutch 1
The transmission torque TA and the bending load of 6e are compared in step (5). If the transmission torque TA is larger than the bending load, the process proceeds to step (6), and the workpiece 20 is bent at high speed. Then , when the ram 5 reaches the bottom dead center in step (7) and the bending of the workpiece 20 is completed, the ram 5 is raised at a high speed in step (8), and the ram 5 is moved to the top dead center in step (9). When stopped, one step of bending is completed.

As described above, when the bending load of the work 20 is small, the high-speed gear 16c is automatically selected and the bending is performed at a high speed. In step (5), the transmission torque TA of the high-speed clutch 16e is bent. If it is determined that the load is smaller than the load, the high-speed clutch 16e is turned off in step (10), the low-speed clutch 16f is turned on in step (11), and the low-speed gear 16d is selected. This allows for Ram 5
Is lowered at a low speed, and the work 20 is bent in step (12). When the ram 5 reaches the bottom dead center in step (13) and the bending is completed, step (14) is performed.
The low speed clutch 16f is turned off, the high speed clutch 16e is turned on in step (15), and the ram 5 is raised to the top dead center at a high speed.

That is , during the bending, the high-speed clutch 16
If it is determined that the transmission torque TA of e is smaller than the bending load, the gear is automatically switched to the low-speed gear 16d, and the output of the servo motor 12 is reduced and transmitted to the vertical drive mechanism 4, so that the output is larger than that at the time of high speed. A pressurizing force can be obtained, whereby the bending capacity is increased, and after the bending, the gear is switched to the high-speed gear 16c again to raise the ram 5, so that the productivity is hardly reduced. Incidentally, the ram 5 when the lowering speed of the ram 5 is switched to the low speed in the middle
8 is shown in FIG.

[0015]

According to the present invention, as described in detail above, the lowering speed of the ram is automatically switched to a plurality of stages in accordance with the bending load. Since the bending process can be performed by using, the productivity is improved. In addition , for a work with a large bending load such as a thick plate, a large bending capacity can be obtained by lowering the ram speed during bending, so that a work such as a thick plate can be easily bent. In addition to this, the ram moves up and down at high speed except during bending, so that even if the bending capacity is increased, the productivity is rarely reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a press brake according to an embodiment of the present invention.

FIG. 2 is a side view of a press brake according to one embodiment of the present invention.

FIG. 3 is a detailed view of a vertical drive mechanism of a press brake according to one embodiment of the present invention.

FIG. 4 is a detailed view of a vertical drive mechanism of a press brake according to one embodiment of the present invention.

FIG. 5 is a sectional view of a speed reducer provided in a press brake according to one embodiment of the present invention.

FIG. 6 is a block diagram showing a control system of a press brake according to one embodiment of the present invention.

FIG. 7 is a flowchart showing the operation of the press brake according to one embodiment of the present invention.

FIG. 8 is an operation diagram of a ram of a press brake according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Press brake main body, 1c ... Table, 4 ... Vertical drive mechanism, 5 ... Ram, 12 ... Ball screw, 14 ... Servo motor, 16 ... Reduction gear, 18 ... Upper mold, 19 ... Lower mold,
20: Workpiece, 25: Torque detector, 26: Control device.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 5/02 B30B 1/18 B30B 15/14

Claims (1)

(57) [Claims] 1. A ball screw for rotating a servomotor.
The ram is moved up and down by a vertical drive mechanism consisting of
On the table of the mounted upper die and press brake body
Work is bent between the lower mold fixed to
In the method for processing a press brake, the ram is lowered at a high speed, and the upper die attached to the ram is removed.
A first step of bringing the work closer to the work, and bending the work between the lower mold and the upper mold in contact with the work.
At the start of the work, the transmission torque of the motor that drives the ram
Torque with a torque detector, convert to pressurized load and determine
When the pressure load is greater than the predetermined bending load,
The motor and the up-down drive mechanism
The speed of the motor is reduced
The transmission is switched to low speed and high torque,
Bending the workpiece, and when the pressure load is smaller than the predetermined bending load,
Judges the bending of the plate and bends the workpiece at high speed without deceleration by the reducer
A second step of selectively and automatically performing a step of performing machining
Press brake machining method characterized by having
Law.